this should fix notice on PHP5.4 & 5.5 in case a value of the array is an array

core/Plugin/Visualization.php

@@ -439,10 +439,10 @@ class Visualization extends ViewDataTable
 
     private function logMessageIfRequestPropertiesHaveChanged(array $requestPropertiesBefore)
     {
-        return;
         $requestProperties = $this->requestConfig->getProperties();
 
-        $diff = array_diff_assoc($requestProperties, $requestPropertiesBefore);
+        $diff = array_diff_assoc($this->makeSureArrayContainsOnlyStrings($requestProperties),
+                                 $this->makeSureArrayContainsOnlyStrings($requestPropertiesBefore));
 
         if (empty($diff)) {
             return;
@@ -462,4 +462,15 @@ class Visualization extends ViewDataTable
 
         Log::warning($message);
     }
+
+    private function makeSureArrayContainsOnlyStrings($array)
+    {
+        $result = array();
+
+        foreach ($array as $key => $value) {
+            $result[$key] = json_encode($value);
+        }
+
+        return $result;
+    }
 }
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