diff --git a/lib/Controller/GebruikController.php b/lib/Controller/GebruikController.php
index 901b31c3..d4e6923d 100644
--- a/lib/Controller/GebruikController.php
+++ b/lib/Controller/GebruikController.php
@@ -70,6 +70,11 @@ public function getGebruiken(): JSONResponse
     {
         $user = $this->userSession->getUser();
 
+        // Return empty results for non-logged-in users to prevent unnecessary errors.
+        if ($user === null) {
+            return new JSONResponse($this->getEmptyResult());
+        }
+
         $groups = $this->groupManager->getUserGroups(user: $user);
         $groupNames = array_map(function (IGroup $group) {
             return $group->getGID();
@@ -85,17 +90,17 @@ public function getGebruiken(): JSONResponse
             $applicatieIds = $this->gebruikService->getApplicationIds(options: $applicatieOptions);
 
             if ($applicatieIds === []) {
-                return new JSONResponse(data: ['error' => 'no access'], statusCode: 403);
+                return new JSONResponse($this->getEmptyResult());
             }
 
             if (isset($options['module']) === true && in_array($options['module'], $applicatieIds) === false) {
-                return new JSONResponse(data: ['error' => 'no access'], statusCode: 403);
+                return new JSONResponse($this->getEmptyResult());
             } else if (isset($options['module']) === false) {
                 $options['module'] = $applicatieIds;
             }
 
         } else {
-            return new JSONResponse(data: ['error' => 'no access'], statusCode: 403);
+            return new JSONResponse($this->getEmptyResult());
         }
 
         try {
@@ -116,6 +121,12 @@ public function getGebruiken(): JSONResponse
     public function getGebruikenForDeelnemer(): JSONResponse
     {
         $user = $this->userSession->getUser();
+
+        // Return empty results for non-logged-in users to prevent unnecessary errors.
+        if ($user === null) {
+            return new JSONResponse($this->getEmptyResult());
+        }
+
         $orgUuid = $this->config->getUserValue(userId: $user->getUID(), appName: 'core', key: 'organisation');
 
         $options = $this->request->getParams();
@@ -128,6 +139,32 @@ public function getGebruikenForDeelnemer(): JSONResponse
         }
     }
 
+    /**
+     * Returns an empty result set with the standard paginated response structure.
+     *
+     * @return array The empty result structure.
+     */
+    private function getEmptyResult(): array
+    {
+        return [
+            'results' => [],
+            'total'   => 0,
+            'page'    => 1,
+            'pages'   => 0,
+            'limit'   => 1000,
+            'offset'  => 0,
+            'facets'  => [],
+            '@self'   => [
+                'source'    => 'database',
+                'query'     => [],
+                'rbac'      => false,
+                'multi'     => false,
+                'published' => false,
+                'deleted'   => false,
+            ],
+        ];
+    }
+
 
 
 }
diff --git a/lib/Service/GebruikService.php b/lib/Service/GebruikService.php
index 9918e8b3..58daa190 100644
--- a/lib/Service/GebruikService.php
+++ b/lib/Service/GebruikService.php
@@ -104,6 +104,17 @@ public function getGebruiken(array $options): array
             'schema' => $gebruiksConfig['gebruikSchema'],
         ];
 
+        // Normalize _extend parameter to array format.
+        // Supports both 'extend' and '_extend' parameter names.
+        $extend = $options['extend'] ?? $options['_extend'] ?? [];
+        if (is_string($extend) === true) {
+            $extend = array_map('trim', explode(',', $extend));
+        } else if (is_array($extend) === false) {
+            $extend = [$extend];
+        }
+        $options['_extend'] = $extend;
+        unset($options['extend']);
+
         $searchResult = $objectService->searchObjectsPaginated(query: $options, _rbac: false, _multitenancy: false);
 
         $searchResult['results'] = array_map(function($object) {
diff --git a/lib/Service/ModuleComplianceService.php b/lib/Service/ModuleComplianceService.php
index b8d67d99..f2674aeb 100644
--- a/lib/Service/ModuleComplianceService.php
+++ b/lib/Service/ModuleComplianceService.php
@@ -114,7 +114,7 @@ public function handleModuleComplianceUpdate(object $moduleObject): void
             ]);
 
             // Get current standaarden from module
-            $currentStandaarden = $moduleData['standaarden'] ?? [];
+            $currentStandaarden = $moduleData['standaardVersies'] ?? [];
             
             // Ensure currentStandaarden is an array
             if (!is_array($currentStandaarden)) {
@@ -360,13 +360,13 @@ private function updateModuleStandaarden(object $moduleObject, array $standaardv
             $moduleData = $moduleObject->getObject();
             
             // Update standaarden property
-            $moduleData['standaarden'] = $standaardversieUuids;
+            $moduleData['standaardVersies'] = $standaardversieUuids;
             
             // Get register ID from module object
             $registerId = $moduleObject->getRegister();
             
             // Save the updated module
-            $objectService->saveObject(
+            $savedObject = $objectService->saveObject(
                 object: $moduleData,
                 extend: [],
                 register: $registerId,
@@ -586,7 +586,7 @@ public function bulkSyncModuleStandards(): array
                     }
 
                     // Get current standaarden from module
-                    $currentStandaarden = $moduleData['standaarden'] ?? [];
+                    $currentStandaarden = $moduleData['standaardVersies'] ?? [];
                     
                     // Ensure currentStandaarden is an array
                     if (!is_array($currentStandaarden)) {
diff --git a/lib/Settings/Settings/softwarecatalogus_register.json b/lib/Settings/Settings/softwarecatalogus_register.json
index 74777d93..c8bd78bd 100644
--- a/lib/Settings/Settings/softwarecatalogus_register.json
+++ b/lib/Settings/Settings/softwarecatalogus_register.json
@@ -5418,6 +5418,23 @@
               "type": "string"
             }
           },
+          "standaardVersies": {
+            "description": "De standaardversies die deze applicatie implementeert",
+            "type": "array",
+            "visible": true,
+            "order": 26,
+            "facetable": true,
+            "title": "Standaard Versies",
+            "hideOnForm": true,
+            "items": {
+              "type": "object",
+              "objectConfiguration": {
+                "handling": "related-object",
+                "queryParams": "gemmaType=standaardversie"
+              },
+              "$ref": "#/components/schemas/element"
+            }
+          },
           "moduleVersies": {
             "description": "De versies van deze applicatie",
             "type": "array",
diff --git a/lib/Settings/softwarecatalogus_register.json b/lib/Settings/softwarecatalogus_register.json
index 504fa851..4421273f 100644
--- a/lib/Settings/softwarecatalogus_register.json
+++ b/lib/Settings/softwarecatalogus_register.json
@@ -5724,6 +5724,23 @@
               "type": "string"
             }
           },
+          "standaardVersies": {
+            "description": "De standaardversies die deze applicatie implementeert",
+            "type": "array",
+            "visible": true,
+            "order": 26,
+            "facetable": true,
+            "title": "Standaard Versies",
+            "hideOnForm": true,
+            "items": {
+              "type": "object",
+              "objectConfiguration": {
+                "handling": "related-object",
+                "queryParams": "gemmaType=standaardversie"
+              },
+              "$ref": "#/components/schemas/element"
+            }
+          },
           "moduleVersies": {
             "description": "De versies van deze applicatie",
             "type": "array",