diff --git a/Classes/Controller/AdminModuleController.php b/Classes/Controller/AdminModuleController.php
index 638b915..cda36e3 100644
--- a/Classes/Controller/AdminModuleController.php
+++ b/Classes/Controller/AdminModuleController.php
@@ -112,21 +112,24 @@ protected function debugAction(
         ServerRequestInterface $request,
         ModuleTemplate $view,
     ): ResponseInterface {
-        $cmd = $request->getParsedBody()['tx_examples_admin_examples']['cmd'] ?? 'cookies';
-        switch ($cmd) {
-            case 'cookies':
-                $this->debugCookies();
-                break;
-            default:
-                // do something else
+        $body = $request->getParsedBody();
+        if (is_array($body)) {
+            $cmd = $body['tx_examples_admin_examples']['cmd'] ?? 'cookies';
+            switch ($cmd) {
+                case 'cookies':
+                    $this->debugCookies();
+                    break;
+                default:
+                    // do something else
+            }
+
+            $view->assignMultiple(
+                [
+                    'cookies' => $request->getCookieParams(),
+                    'lastcommand' => $cmd,
+                ],
+            );
         }
-
-        $view->assignMultiple(
-            [
-                'cookies' => $request->getCookieParams(),
-                'lastcommand' => $cmd,
-            ],
-        );
         return $view->renderResponse('AdminModule/Debug');
     }
 
diff --git a/Classes/Controller/ModuleController.php b/Classes/Controller/ModuleController.php
index 33918ff..bb7eba5 100644
--- a/Classes/Controller/ModuleController.php
+++ b/Classes/Controller/ModuleController.php
@@ -63,7 +63,6 @@ public function __construct(
         protected readonly ResourceFactory $resourceFactory,
         protected readonly FileRepository $fileRepository,
         protected readonly ConnectionPool $connectionPool,
-        protected readonly DataHandler $dataHandler,
         protected readonly TableInformationService $tableInformationService,
         private readonly LoggerInterface $logger,
     ) {}
@@ -458,10 +457,15 @@ public function fileReferenceCreateAction(
             'image' => $newId, // For multiple new references $newId is a comma-separated list
         ];
         //  process the data
-        $this->dataHandler->start($data, []);
-        $this->dataHandler->process_datamap();
+
+        /** @var DataHandler $dataHandler */
+        // Do not inject or reuse the DataHander as it holds state!
+        // Do not use `new` as GeneralUtility::makeInstance handles dependencies
+        $dataHandler = GeneralUtility::makeInstance(DataHandler::class);
+        $dataHandler->start($data, []);
+        $dataHandler->process_datamap();
         // Error or success reporting
-        if (count($this->dataHandler->errorLog) === 0) {
+        if (count($dataHandler->errorLog) === 0) {
             $this->addFlashMessage(
                 LocalizationUtility::translate(
                     'create_relation_success',
@@ -470,7 +474,7 @@ public function fileReferenceCreateAction(
                 '',
             );
         } else {
-            foreach ($this->dataHandler->errorLog as $log) {
+            foreach ($dataHandler->errorLog as $log) {
                 $this->addFlashMessage(
                     $log,
                     LocalizationUtility::translate(