diff --git a/Classes/Controller/JsonApiCollectionCommandController.php b/Classes/Controller/JsonApiCollectionCommandController.php
index 20350ec..d7bbd7b 100644
--- a/Classes/Controller/JsonApiCollectionCommandController.php
+++ b/Classes/Controller/JsonApiCollectionCommandController.php
@@ -41,9 +41,9 @@ public function read(ServerRequestInterface $request): ResponseInterface
         $this->parseFieldsets($queryParams);
 
         $pageParams = $queryParams['page'] ?? [];
-        $currentCursor = $pageParams['cursor'];
-        $previousCursor = $pageParams['previous'];
-        $limit = $pageParams['limit'] ? (int) $pageParams['limit'] : 10;
+        $currentCursor = $pageParams['cursor'] ?? null;
+        $previousCursor = $pageParams['previous'] ?? null;
+        $limit = isset($pageParams['limit']) ? (int) $pageParams['limit'] : 10;
 
         $filters = isset($queryParams['filter']) && \is_array($queryParams['filter']) ? $queryParams['filter'] : [];
 
diff --git a/Classes/Controller/JsonApiItemCommandController.php b/Classes/Controller/JsonApiItemCommandController.php
index 6e55b24..d2ebf9a 100644
--- a/Classes/Controller/JsonApiItemCommandController.php
+++ b/Classes/Controller/JsonApiItemCommandController.php
@@ -53,7 +53,8 @@ public function read(ServerRequestInterface $request): ResponseInterface
 
         $resourceIdentifier = \urldecode($request->getAttribute('variables')['id'] ?: '');
 
-        $data = $this->fetchAndTransformData($resourceIdentifier, $request->getAttributes()['context']);
+        $context = $request->getAttributes()['context'] ?? null;
+        $data = $this->fetchAndTransformData($resourceIdentifier, $context);
 
         if (null === $data) {
             return new JsonResponse($data, 404, ['Content-Type' => 'application/vnd.api+json; charset=utf-8']);
diff --git a/Classes/IncludeHandler/TcaResourceIncludeHandler.php b/Classes/IncludeHandler/TcaResourceIncludeHandler.php
index fd6c145..389bd87 100644
--- a/Classes/IncludeHandler/TcaResourceIncludeHandler.php
+++ b/Classes/IncludeHandler/TcaResourceIncludeHandler.php
@@ -125,7 +125,7 @@ protected function buildTcaIncludes($tableName): array
 
                         break;
                     case 'group':
-                        if ('db' === $columnConfig['internal_type'] && !empty($columnConfig['allowed']) && false === \strpos($columnConfig['allowed'], ',')) {
+                        if ('db' === ($columnConfig['internal_type'] ?? null) && !empty($columnConfig['allowed']) && false === \strpos($columnConfig['allowed'], ',')) {
                             return \array_merge($columnConfig, [static::REFERENCE_TABLE_NAME => GeneralUtility::trimExplode(',', $columnConfig['allowed'], true)]);
                         }