diff --git a/system/src/Grav/Common/Cache.php b/system/src/Grav/Common/Cache.php
index 1e693af3b..5bf3f7608 100644
--- a/system/src/Grav/Common/Cache.php
+++ b/system/src/Grav/Common/Cache.php
@@ -319,7 +319,7 @@ class Cache extends Getters
      *
      * @param  string $id the id of the cached entry
      *
-     * @return object|bool     returns the cached entry, can be any type, or false if doesn't exist
+     * @return mixed|bool     returns the cached entry, can be any type, or false if doesn't exist
      */
     public function fetch($id)
     {
diff --git a/system/src/Grav/Common/Errors/Errors.php b/system/src/Grav/Common/Errors/Errors.php
index dbc955ed0..2f71be5a1 100644
--- a/system/src/Grav/Common/Errors/Errors.php
+++ b/system/src/Grav/Common/Errors/Errors.php
@@ -40,23 +40,23 @@ class Errors
                 $error_page->setPageTitle('Crikey! There was an error...');
                 $error_page->addResourcePath(GRAV_ROOT . '/system/assets');
                 $error_page->addCustomCss('whoops.css');
-                $whoops->pushHandler($error_page);
+                $whoops->prependHandler($error_page);
                 break;
             case -1:
-                $whoops->pushHandler(new BareHandler);
+                $whoops->prependHandler(new BareHandler);
                 break;
             default:
-                $whoops->pushHandler(new SimplePageHandler);
+                $whoops->prependHandler(new SimplePageHandler);
                 break;
         }
 
         if (Whoops\Util\Misc::isAjaxRequest() || $jsonRequest) {
-            $whoops->pushHandler(new Whoops\Handler\JsonResponseHandler);
+            $whoops->prependHandler(new Whoops\Handler\JsonResponseHandler);
         }
 
         if (isset($config['log']) && $config['log']) {
             $logger = $grav['log'];
-            $whoops->pushHandler(function($exception, $inspector, $run) use ($logger) {
+            $whoops->prependHandler(function($exception, $inspector, $run) use ($logger) {
                 try {
                     $logger->addCritical($exception->getMessage() . ' - Trace: ' . $exception->getTraceAsString());
                 } catch (\Exception $e) {
diff --git a/system/src/Grav/Common/Media/Traits/MediaTrait.php b/system/src/Grav/Common/Media/Traits/MediaTrait.php
index e5bca147b..46e1dcd15 100644
--- a/system/src/Grav/Common/Media/Traits/MediaTrait.php
+++ b/system/src/Grav/Common/Media/Traits/MediaTrait.php
@@ -67,7 +67,7 @@ trait MediaTrait
     /**
      * Gets the associated media collection.
      *
-     * @return MediaCollectionInterface  Representation of associated media.
+     * @return MediaCollectionInterface|Media  Representation of associated media.
      */
     public function getMedia()
     {
@@ -89,7 +89,7 @@ trait MediaTrait
     /**
      * Sets the associated media collection.
      *
-     * @param  MediaCollectionInterface  $media Representation of associated media.
+     * @param  MediaCollectionInterface|Media  $media Representation of associated media.
      * @return $this
      */
     protected function setMedia(MediaCollectionInterface $media)
diff --git a/system/src/Grav/Common/Page/Interfaces/PageCollectionInterface.php b/system/src/Grav/Common/Page/Interfaces/PageCollectionInterface.php
index f4203fb46..a47a0c747 100644
--- a/system/src/Grav/Common/Page/Interfaces/PageCollectionInterface.php
+++ b/system/src/Grav/Common/Page/Interfaces/PageCollectionInterface.php
@@ -253,6 +253,13 @@ interface PageCollectionInterface extends \Traversable, \ArrayAccess, \Countable
      */
     public function ofOneOfTheseAccessLevels($accessLevels);
 
+    /**
+     * Converts collection into an array.
+     *
+     * @return array
+     */
+    public function toArray();
+
     /**
      * Get the extended version of this Collection with each page keyed by route
      *
diff --git a/system/src/Grav/Common/Page/Interfaces/PageContentInterface.php b/system/src/Grav/Common/Page/Interfaces/PageContentInterface.php
index 045d46123..c7de508e4 100644
--- a/system/src/Grav/Common/Page/Interfaces/PageContentInterface.php
+++ b/system/src/Grav/Common/Page/Interfaces/PageContentInterface.php
@@ -9,7 +9,7 @@
 
 namespace Grav\Common\Page\Interfaces;
 
-use Grav\Common\Page\Media;
+use Grav\Common\Media\Interfaces\MediaCollectionInterface;
 
 /**
  * Methods currently implemented in Flex Page emulation layer.
@@ -20,7 +20,6 @@ interface PageContentInterface
      * Gets and Sets the header based on the YAML configuration at the top of the .md file
      *
      * @param  object|array $var a YAML object representing the configuration for the file
-     *
      * @return object      the current YAML configuration
      */
     public function header($var = null);
@@ -28,10 +27,8 @@ interface PageContentInterface
     /**
      * Get the summary.
      *
-     * @param  int $size Max summary size.
-     *
+     * @param int|null $size Max summary size.
      * @param bool $textOnly Only count text size.
-     *
      * @return string
      */
     public function summary($size = null, $textOnly = false);
@@ -46,8 +43,7 @@ interface PageContentInterface
     /**
      * Gets and Sets the content based on content portion of the .md file
      *
-     * @param  string $var Content
-     *
+     * @param  string|null $var Content
      * @return string      Content
      */
     public function content($var = null);
@@ -70,7 +66,6 @@ interface PageContentInterface
      * Gets and Sets the Page raw content
      *
      * @param string|null $var
-     *
      * @return string
      */
     public function rawMarkdown($var = null);
@@ -79,7 +74,7 @@ interface PageContentInterface
      * Get value from a page variable (used mostly for creating edit forms).
      *
      * @param string $name Variable name.
-     * @param mixed $default
+     * @param mixed|null $default
      *
      * @return mixed
      */
@@ -88,18 +83,16 @@ interface PageContentInterface
     /**
      * Gets and sets the associated media as found in the page folder.
      *
-     * @param  Media $var Representation of associated media.
-     *
-     * @return Media      Representation of associated media.
+     * @param  MediaCollectionInterface|null $var New media object.
+     * @return MediaCollectionInterface           Representation of associated media.
      */
     public function media($var = null);
 
     /**
      * Gets and sets the title for this Page.  If no title is set, it will use the slug() to get a name
      *
-     * @param  string $var the title of the Page
-     *
-     * @return string      the title of the Page
+     * @param  string|null $var New title of the Page
+     * @return string           The title of the Page
      */
     public function title($var = null);
 
@@ -107,45 +100,40 @@ interface PageContentInterface
      * Gets and sets the menu name for this Page.  This is the text that can be used specifically for navigation.
      * If no menu field is set, it will use the title()
      *
-     * @param  string $var the menu field for the page
-     *
-     * @return string      the menu field for the page
+     * @param  string|null $var New menu field for the page
+     * @return string           The menu field for the page
      */
     public function menu($var = null);
 
     /**
      * Gets and Sets whether or not this Page is visible for navigation
      *
-     * @param  bool $var true if the page is visible
-     *
-     * @return bool      true if the page is visible
+     * @param  bool|null $var   New value
+     * @return bool             True if the page is visible
      */
     public function visible($var = null);
 
     /**
      * Gets and Sets whether or not this Page is considered published
      *
-     * @param  bool $var true if the page is published
-     *
-     * @return bool      true if the page is published
+     * @param  bool|null $var   New value
+     * @return bool             True if the page is published
      */
     public function published($var = null);
 
     /**
      * Gets and Sets the Page publish date
      *
-     * @param  string $var string representation of a date
-     *
-     * @return int         unix timestamp representation of the date
+     * @param  string|null $var String representation of the new date
+     * @return int              Unix timestamp representation of the date
      */
     public function publishDate($var = null);
 
     /**
      * Gets and Sets the Page unpublish date
      *
-     * @param  string $var string representation of a date
-     *
-     * @return int|null         unix timestamp representation of the date
+     * @param  string|null $var String representation of the new date
+     * @return int|null         Unix timestamp representation of the date
      */
     public function unpublishDate($var = null);
 
@@ -153,9 +141,8 @@ interface PageContentInterface
      * Gets and Sets the process setup for this Page. This is multi-dimensional array that consists of
      * a simple array of arrays with the form array("markdown"=>true) for example
      *
-     * @param  array $var an Array of name value pairs where the name is the process and value is true or false
-     *
-     * @return array      an Array of name value pairs where the name is the process and value is true or false
+     * @param  array|null $var New array of name value pairs where the name is the process and value is true or false
+     * @return array            Array of name value pairs where the name is the process and value is true or false
      */
     public function process($var = null);
 
@@ -163,63 +150,56 @@ interface PageContentInterface
      * Gets and Sets the slug for the Page. The slug is used in the URL routing. If not set it uses
      * the parent folder from the path
      *
-     * @param  string $var the slug, e.g. 'my-blog'
-     *
-     * @return string      the slug
+     * @param  string|null $var New slug, e.g. 'my-blog'
+     * @return string           The slug
      */
     public function slug($var = null);
 
     /**
      * Get/set order number of this page.
      *
-     * @param int $var
-     *
-     * @return string|bool
+     * @param int|null $var      New order as a number
+     * @return string|bool       Order in a form of '02.' or false if not set
      */
     public function order($var = null);
 
     /**
      * Gets and sets the identifier for this Page object.
      *
-     * @param  string $var the identifier
-     *
-     * @return string      the identifier
+     * @param  string|null $var New identifier
+     * @return string           The identifier
      */
     public function id($var = null);
 
     /**
      * Gets and sets the modified timestamp.
      *
-     * @param  int $var modified unix timestamp
-     *
-     * @return int      modified unix timestamp
+     * @param  int|null $var New modified unix timestamp
+     * @return int           Modified unix timestamp
      */
     public function modified($var = null);
 
     /**
      * Gets and sets the option to show the last_modified header for the page.
      *
-     * @param  boolean $var show last_modified header
-     *
-     * @return boolean      show last_modified header
+     * @param  bool|null $var New last_modified header value
+     * @return bool           Show last_modified header
      */
     public function lastModified($var = null);
 
     /**
      * Get/set the folder.
      *
-     * @param string $var Optional path
-     *
-     * @return string|null
+     * @param string|null $var New folder
+     * @return string|null     The folder
      */
     public function folder($var = null);
 
     /**
      * Gets and sets the date for this Page object. This is typically passed in via the page headers
      *
-     * @param  string $var string representation of a date
-     *
-     * @return int         unix timestamp representation of the date
+     * @param  string|null $var New string representation of a date
+     * @return int              Unix timestamp representation of the date
      */
     public function date($var = null);
 
@@ -227,27 +207,24 @@ interface PageContentInterface
      * Gets and sets the date format for this Page object. This is typically passed in via the page headers
      * using typical PHP date string structure - http://php.net/manual/en/function.date.php
      *
-     * @param  string $var string representation of a date format
-     *
-     * @return string      string representation of a date format
+     * @param  string|null $var New string representation of a date format
+     * @return string           String representation of a date format
      */
     public function dateformat($var = null);
 
     /**
      * Gets and sets the taxonomy array which defines which taxonomies this page identifies itself with.
      *
-     * @param  array $var an array of taxonomies
-     *
-     * @return array      an array of taxonomies
+     * @param  array|null $var  New array of taxonomies
+     * @return array            An array of taxonomies
      */
     public function taxonomy($var = null);
 
     /**
      * Gets the configured state of the processing method.
      *
-     * @param  string $process the process, eg "twig" or "markdown"
-     *
-     * @return bool            whether or not the processing method is enabled for this Page
+     * @param  string $process The process name, eg "twig" or "markdown"
+     * @return bool            Whether or not the processing method is enabled for this Page
      */
     public function shouldProcess($process);
 
diff --git a/system/src/Grav/Common/Page/Interfaces/PageFormInterface.php b/system/src/Grav/Common/Page/Interfaces/PageFormInterface.php
index 0c413ce5a..8b94c2379 100644
--- a/system/src/Grav/Common/Page/Interfaces/PageFormInterface.php
+++ b/system/src/Grav/Common/Page/Interfaces/PageFormInterface.php
@@ -16,7 +16,6 @@ interface PageFormInterface
      * Add forms to this page.
      *
      * @param array $new
-     * @param bool $override
      * @return $this
      */
     public function addForms(array $new/*, $override = true*/);
diff --git a/system/src/Grav/Common/Page/Page.php b/system/src/Grav/Common/Page/Page.php
index e8c761613..5e6e254df 100644
--- a/system/src/Grav/Common/Page/Page.php
+++ b/system/src/Grav/Common/Page/Page.php
@@ -1212,8 +1212,7 @@ class Page implements PageInterface
      * Gets and sets the associated media as found in the page folder.
      *
      * @param  Media $var Representation of associated media.
-     *
-     * @return MediaCollectionInterface|Media      Representation of associated media.
+     * @return Media      Representation of associated media.
      */
     public function media($var = null)
     {
diff --git a/system/src/Grav/Common/Page/Pages.php b/system/src/Grav/Common/Page/Pages.php
index 0abe91288..c7d22249b 100644
--- a/system/src/Grav/Common/Page/Pages.php
+++ b/system/src/Grav/Common/Page/Pages.php
@@ -517,7 +517,7 @@ class Pages
     }
 
     /**
-     * @param $value
+     * @param array|string $value
      * @param PageInterface|null $self
      * @return Collection
      */
@@ -702,11 +702,8 @@ class Pages
         $instance = $this->instances[(string)$path] ?? null;
         if (\is_string($instance)) {
             $instance = $this->flex ? $this->flex->getObject($instance) : null;
-            if ($instance) {
-                $instance = $instance->hasTranslation() ? $instance->getTranslation() : $instance;
-                if (method_exists($instance, 'initialize') && $this->grav['config']->get('system.pages.events.page')) {
-                    $instance->initialize();
-                }
+            if (method_exists($instance, 'initialize') && $this->grav['config']->get('system.pages.events.page')) {
+                $instance->initialize();
             }
         }
         if ($instance && !$instance instanceof PageInterface) {
@@ -1329,6 +1326,15 @@ class Pages
          * @var PageInterface|FlexObjectInterface $page
          */
         foreach ($collection as $key => $page) {
+            $path = $page->path();
+
+            // FIXME: We really need to do better than this.
+            $page = $page->hasTranslation() ? $page->getTranslation() : null;
+
+            if (!$page || $path === $root_path) {
+                continue;
+            }
+
             if ($config->get('system.pages.events.page')) {
                 if (method_exists($page, 'initialize')) {
                     $page->initialize();
@@ -1338,19 +1344,11 @@ class Pages
                 }
             }
 
-            $path = $page->path();
-
-            // FIXME: We really need to do better than this.
-            $translated = $page->hasTranslation() ? $page->getTranslation() : false;
-
-            if (!$translated || $path === $root_path) {
-                continue;
-            }
             $parent = dirname($path);
 
             $this->instances[$path] = $page->getFlexKey();
             // FIXME: ... better...
-            $this->children[$parent][$path] = ['slug' => $translated->slug()];
+            $this->children[$parent][$path] = ['slug' => $page->slug()];
             if (!isset($this->children[$path])) {
                 $this->children[$path] = [];
             }
@@ -1372,7 +1370,7 @@ class Pages
         $this->buildRoutes();
 
         // cache if needed
-        if (isset($cache)) {
+        if (null !== $cache) {
             /** @var Taxonomy $taxonomy */
             $taxonomy = $this->grav['taxonomy'];
             $taxonomy_map = $taxonomy->taxonomy();
diff --git a/system/src/Grav/Common/Security.php b/system/src/Grav/Common/Security.php
index 5f07c3ce6..581d5e774 100644
--- a/system/src/Grav/Common/Security.php
+++ b/system/src/Grav/Common/Security.php
@@ -18,7 +18,7 @@ class Security
     /**
      * Sanitize SVG for XSS code
      *
-     * @param $file
+     * @param string $file
      */
     public static function sanitizeSVG($file)
     {
diff --git a/system/src/Grav/Common/User/DataUser/User.php b/system/src/Grav/Common/User/DataUser/User.php
index 696ad87a3..fbe666def 100644
--- a/system/src/Grav/Common/User/DataUser/User.php
+++ b/system/src/Grav/Common/User/DataUser/User.php
@@ -15,7 +15,7 @@ use Grav\Common\Data\Data;
 use Grav\Common\File\CompiledYamlFile;
 use Grav\Common\Grav;
 use Grav\Common\Page\Media;
-use Grav\Common\Page\Medium\ImageMedium;
+use Grav\Common\Page\Medium\Medium;
 use Grav\Common\Page\Medium\MediumFactory;
 use Grav\Common\User\Authentication;
 use Grav\Common\User\Interfaces\UserInterface;
diff --git a/system/src/Grav/Common/User/FlexUser/User.php b/system/src/Grav/Common/User/FlexUser/User.php
index 46787d271..cb4b7e6c0 100644
--- a/system/src/Grav/Common/User/FlexUser/User.php
+++ b/system/src/Grav/Common/User/FlexUser/User.php
@@ -544,8 +544,12 @@ class User extends FlexObject implements UserInterface, MediaManipulationInterfa
         return \count($this->jsonSerialize());
     }
 
+    /**
+     * @return MediaCollectionInterface
+     */
     public function getMedia()
     {
+        /** @var Media $media */
         $media = $this->getFlexMedia();
 
         // Deal with shared avatar folder.
diff --git a/system/src/Grav/Common/Utils.php b/system/src/Grav/Common/Utils.php
index e639ccbcf..9288dd7ce 100644
--- a/system/src/Grav/Common/Utils.php
+++ b/system/src/Grav/Common/Utils.php
@@ -56,6 +56,7 @@ abstract class Utils
         /** @var Uri $uri */
         $uri = $grav['uri'];
 
+        $resource = false;
         if (static::contains((string)$input, '://')) {
             /** @var UniformResourceLocator $locator */
             $locator = $grav['locator'];
@@ -331,7 +332,7 @@ abstract class Utils
      * @param array $a
      * @return array|false
      */
-    public static function arrayLower(Array $a)
+    public static function arrayLower(array $a)
     {
         return array_map('mb_strtolower', $a);
     }
@@ -339,11 +340,11 @@ abstract class Utils
     /**
      * Simple function to remove item/s in an array by value
      *
-     * @param $search array
-     * @param $value string|array
+     * @param array $search
+     * @param string|array $value
      * @return array
      */
-    public static function arrayRemoveValue(Array $search, $value)
+    public static function arrayRemoveValue(array $search, $value)
     {
         foreach ((array) $value as $val) {
             $key = array_search($val, $search);
diff --git a/system/src/Grav/Console/Cli/PageSystemValidatorCommand.php b/system/src/Grav/Console/Cli/PageSystemValidatorCommand.php
index 9d9e1cc3b..b946ddf9d 100644
--- a/system/src/Grav/Console/Cli/PageSystemValidatorCommand.php
+++ b/system/src/Grav/Console/Cli/PageSystemValidatorCommand.php
@@ -121,6 +121,9 @@ class PageSystemValidatorCommand extends ConsoleCommand
         //'getAction' => [[]],
     ];
 
+    /** @var Grav */
+    protected $grav;
+
     protected function configure()
     {
         $this
diff --git a/system/src/Grav/Console/Cli/ServerCommand.php b/system/src/Grav/Console/Cli/ServerCommand.php
index ab7caa75c..d5b6add0a 100644
--- a/system/src/Grav/Console/Cli/ServerCommand.php
+++ b/system/src/Grav/Console/Cli/ServerCommand.php
@@ -27,7 +27,9 @@ class ServerCommand extends ConsoleCommand
     const SYMFONY_SERVER = 'Symfony Server';
     const PHP_SERVER = 'Built-in PHP Server';
 
+    /** @var string */
     protected $ip;
+    /** @var int */
     protected $port;
     protected $io;
 
@@ -60,16 +62,16 @@ class ServerCommand extends ConsoleCommand
         $php = $executableFinder->find(false);
 
         $this->ip = '127.0.0.1';
-        $this->port = intval($this->input->getOption('port') ?? 8000);
+        $this->port = (int)($this->input->getOption('port') ?? 8000);
 
 
         // Get an open port
         while (!$this->portAvailable($this->ip, $this->port)) {
-            $this->port += 1;
+            $this->port++;
         }
 
         // Setup the commands
-        $symfony_cmd = ['symfony', 'server:start', '--ansi', '--port=' . $this->port ];
+        $symfony_cmd = ['symfony', 'server:start', '--ansi', '--port=' . $this->port];
         $php_cmd = [$php, '-S', $this->ip.':'.$this->port, 'system/router.php'];
 
         $commands = [
@@ -107,7 +109,7 @@ class ServerCommand extends ConsoleCommand
         $process->start();
 
         if ($name === self::PHP_SERVER) {
-            $this->io->success('Built-in PHP web server listening on http://' . $this->ip . ':' . $this->port . ' (PHP v' . phpversion() . ')');
+            $this->io->success('Built-in PHP web server listening on http://' . $this->ip . ':' . $this->port . ' (PHP v' . PHP_VERSION . ')');
         }
 
         $process->wait(function ($type, $buffer) {
@@ -120,18 +122,18 @@ class ServerCommand extends ConsoleCommand
     /**
      * Simple function test the port
      *
-     * @param $ip
-     * @param $port
+     * @param string $ip
+     * @param int $port
      * @return bool
      */
-    protected function portAvailable($ip, $port) {
+    protected function portAvailable($ip, $port)
+    {
         $fp = @fsockopen($ip, $port, $errno, $errstr, 0.1);
         if (!$fp) {
             return true;
-        } else {
-            fclose($fp);
-            return false;
         }
-    }
 
+        fclose($fp);
+        return false;
+    }
 }
diff --git a/system/src/Grav/Framework/Collection/AbstractFileCollection.php b/system/src/Grav/Framework/Collection/AbstractFileCollection.php
index f6f299607..61b3dfeb3 100644
--- a/system/src/Grav/Framework/Collection/AbstractFileCollection.php
+++ b/system/src/Grav/Framework/Collection/AbstractFileCollection.php
@@ -197,7 +197,7 @@ class AbstractFileCollection extends AbstractLazyCollection implements FileColle
     }
 
     /**
-     * @param \RecursiveDirectoryIterator[] $children
+     * @param array $children
      * @return array
      */
     protected function doInitializeChildren(array $children, $nestingLimit)
diff --git a/system/src/Grav/Framework/Collection/AbstractLazyCollection.php b/system/src/Grav/Framework/Collection/AbstractLazyCollection.php
index 0653caa41..250ce8977 100644
--- a/system/src/Grav/Framework/Collection/AbstractLazyCollection.php
+++ b/system/src/Grav/Framework/Collection/AbstractLazyCollection.php
@@ -31,6 +31,7 @@ abstract class AbstractLazyCollection extends BaseAbstractLazyCollection impleme
     public function reverse()
     {
         $this->initialize();
+
         return $this->collection->reverse();
     }
 
@@ -40,6 +41,7 @@ abstract class AbstractLazyCollection extends BaseAbstractLazyCollection impleme
     public function shuffle()
     {
         $this->initialize();
+
         return $this->collection->shuffle();
     }
 
@@ -49,6 +51,7 @@ abstract class AbstractLazyCollection extends BaseAbstractLazyCollection impleme
     public function chunk($size)
     {
         $this->initialize();
+
         return $this->collection->chunk($size);
     }
 
@@ -58,6 +61,7 @@ abstract class AbstractLazyCollection extends BaseAbstractLazyCollection impleme
     public function select(array $keys)
     {
         $this->initialize();
+
         return $this->collection->select($keys);
     }
 
@@ -67,6 +71,7 @@ abstract class AbstractLazyCollection extends BaseAbstractLazyCollection impleme
     public function unselect(array $keys)
     {
         $this->initialize();
+
         return $this->collection->unselect($keys);
     }
 
@@ -76,6 +81,7 @@ abstract class AbstractLazyCollection extends BaseAbstractLazyCollection impleme
     public function jsonSerialize()
     {
         $this->initialize();
+
         return $this->collection->jsonSerialize();
     }
 }
diff --git a/system/src/Grav/Framework/Flex/FlexDirectory.php b/system/src/Grav/Framework/Flex/FlexDirectory.php
index 37de6e9a9..8d7487fe8 100644
--- a/system/src/Grav/Framework/Flex/FlexDirectory.php
+++ b/system/src/Grav/Framework/Flex/FlexDirectory.php
@@ -621,7 +621,9 @@ class FlexDirectory implements FlexAuthorizeInterface
             }
         }
 
-        $fetch && $debugger->stopTimer('flex-objects');
+        if ($fetch) {
+            $debugger->stopTimer('flex-objects');
+        }
 
         return $list;
     }
diff --git a/system/src/Grav/Framework/Flex/FlexFormFlash.php b/system/src/Grav/Framework/Flex/FlexFormFlash.php
index 54ed75d55..819977078 100644
--- a/system/src/Grav/Framework/Flex/FlexFormFlash.php
+++ b/system/src/Grav/Framework/Flex/FlexFormFlash.php
@@ -34,7 +34,7 @@ class FlexFormFlash extends FormFlash
         $serialized = parent::jsonSerialize();
 
         $object = $this->getObject();
-        if ($object) {
+        if ($object instanceof FlexObjectInterface) {
             $serialized['object'] = [
                 'type' => $object->getFlexType(),
                 'key' => $object->getKey() ?: null,
diff --git a/system/src/Grav/Framework/Flex/Interfaces/FlexCollectionInterface.php b/system/src/Grav/Framework/Flex/Interfaces/FlexCollectionInterface.php
index b6eace519..0188401b0 100644
--- a/system/src/Grav/Framework/Flex/Interfaces/FlexCollectionInterface.php
+++ b/system/src/Grav/Framework/Flex/Interfaces/FlexCollectionInterface.php
@@ -121,4 +121,12 @@ interface FlexCollectionInterface extends FlexCommonInterface, ObjectCollectionI
      * @return FlexIndexInterface   Returns a Flex Index from the current collection.
      */
     public function getIndex();
+
+    /**
+     * Get metadata associated to the object
+     *
+     * @param string $key Key.
+     * @return array
+     */
+    public function getMetaData(string $key): array;
 }
diff --git a/system/src/Grav/Framework/Flex/Interfaces/FlexObjectInterface.php b/system/src/Grav/Framework/Flex/Interfaces/FlexObjectInterface.php
index 872150307..e44d2c5d8 100644
--- a/system/src/Grav/Framework/Flex/Interfaces/FlexObjectInterface.php
+++ b/system/src/Grav/Framework/Flex/Interfaces/FlexObjectInterface.php
@@ -55,6 +55,13 @@ interface FlexObjectInterface extends FlexCommonInterface, NestedObjectInterface
      */
     public function search(string $search, $properties = null, array $options = null): float;
 
+    /**
+     * Returns true if object has a key.
+     *
+     * @return bool
+     */
+    public function hasKey();
+
     /**
      * Get a unique key for the object.
      *
diff --git a/system/src/Grav/Framework/Flex/Storage/FolderStorage.php b/system/src/Grav/Framework/Flex/Storage/FolderStorage.php
index 3b4b4a9a3..6f39eaa38 100644
--- a/system/src/Grav/Framework/Flex/Storage/FolderStorage.php
+++ b/system/src/Grav/Framework/Flex/Storage/FolderStorage.php
@@ -380,7 +380,7 @@ class FolderStorage extends AbstractFilesystemStorage
                 $locator->clearCache();
             }
         } catch (\RuntimeException $e) {
-            throw new \RuntimeException(sprintf('Flex saveFile(%s): %s', $file->filename(), $e->getMessage()));
+            throw new \RuntimeException(sprintf('Flex saveFile(%s): %s', $path ?? $key, $e->getMessage()));
         }
 
         $row['__META'] = $this->getObjectMeta($key, true);
diff --git a/system/src/Grav/Framework/Form/FormFlash.php b/system/src/Grav/Framework/Form/FormFlash.php
index c029efb56..bcb79c075 100644
--- a/system/src/Grav/Framework/Form/FormFlash.php
+++ b/system/src/Grav/Framework/Form/FormFlash.php
@@ -30,7 +30,7 @@ class FormFlash implements FormFlashInterface
     protected $formName;
     /** @var string */
     protected $url;
-    /** @var array */
+    /** @var array|null */
     protected $user;
     /** @var int */
     protected $createdTimestamp;
@@ -221,7 +221,7 @@ class FormFlash implements FormFlashInterface
     /**
      * @inheritDoc
      */
-    public function save(bool $force = false): self
+    public function save(bool $force = false)
     {
         if (!($this->folder && $this->uniqueId)) {
             return $this;
@@ -243,7 +243,7 @@ class FormFlash implements FormFlashInterface
     /**
      * @inheritDoc
      */
-    public function delete(): self
+    public function delete()
     {
         if ($this->folder && $this->uniqueId) {
             $this->removeTmpDir();
diff --git a/system/src/Grav/Framework/Form/Traits/FormTrait.php b/system/src/Grav/Framework/Form/Traits/FormTrait.php
index 33990ca52..d596c0a3b 100644
--- a/system/src/Grav/Framework/Form/Traits/FormTrait.php
+++ b/system/src/Grav/Framework/Form/Traits/FormTrait.php
@@ -19,6 +19,7 @@ use Grav\Common\Twig\Twig;
 use Grav\Common\User\Interfaces\UserInterface;
 use Grav\Common\Utils;
 use Grav\Framework\ContentBlock\HtmlBlock;
+use Grav\Framework\Form\Interfaces\FormFlashInterface;
 use Grav\Framework\Form\Interfaces\FormInterface;
 use Grav\Framework\Session\SessionInterface;
 use Psr\Http\Message\ServerRequestInterface;
@@ -54,7 +55,7 @@ trait FormTrait
     private $data;
     /** @var array|UploadedFileInterface[] */
     private $files;
-    /** @var FormFlash|null */
+    /** @var FormFlashInterface|null */
     private $flash;
     /** @var string */
     private $flashFolder;