--- Classes/Adapter/ApplicationType.php 2023-02-24 11:11:59.000000000 +0100
+++ Classes/Adapter/ApplicationType_fixed.php   2023-04-12 10:53:04.597934745 +0200
@@ -30,14 +30,15 @@
         }
 
         if (! $this->applicationType instanceof CoreApplicationType) {
+            if (!(($this->getRequest() ?? null) instanceof ServerRequestInterface)) return false;
             $this->applicationType = CoreApplicationType::fromRequest($this->getRequest());
         }
 
         return $this->applicationType->isBackend();
     }
 
-    private function getRequest(): ServerRequestInterface
+    private function getRequest(): ?ServerRequestInterface
     {
-        return $GLOBALS['TYPO3_REQUEST'];
+        return $GLOBALS['TYPO3_REQUEST']??null;
     }
 }