diff --git a/htdocs/includes/restler/framework/Luracast/Restler/AutoLoader.php b/htdocs/includes/restler/framework/Luracast/Restler/AutoLoader.php
index 5ed160a070a..765927bbf88 100644
--- a/htdocs/includes/restler/framework/Luracast/Restler/AutoLoader.php
+++ b/htdocs/includes/restler/framework/Luracast/Restler/AutoLoader.php
@@ -290,10 +290,14 @@ class AutoLoader
         if (is_array($loader)
             && is_callable($loader)) {
             $b = new $loader[0];
-            if (false !== $file = $b::$loader[1]($className)
-                    && $this->exists($className, $b::$loader[1])) {
-                return $file;
-            }
+			//avoid PHP Fatal error:  Uncaught Error: Access to undeclared static property: Composer\\Autoload\\ClassLoader::$loader
+			//in case of multiple autoloader systems
+			if(property_exists($b, $loader[1])) {
+				if (false !== $file = $b::$loader[1]($className)
+					&& $this->exists($className, $b::$loader[1])) {
+				return $file;
+				}
+			}
         } elseif (is_callable($loader)
             && false !== $file = $loader($className)
                 && $this->exists($className, $loader)) {