[TASK] Check for the existence of the project_base to prevent crashes

Classes/Controller/JoblistController.php

@@ -41,6 +41,7 @@ use TYPO3\CMS\Core\Core\Environment;
 use TYPO3\CMS\Core\Http\ImmediateResponseException;
 use TYPO3\CMS\Core\Resource\ResourceFactory;
 use TYPO3\CMS\Core\Site\SiteFinder;
+use TYPO3\CMS\Core\Utility\ExtensionManagementUtility;
 use TYPO3\CMS\Core\Utility\GeneralUtility;
 use TYPO3\CMS\Extbase\Configuration\ConfigurationManagerInterface;
 use TYPO3\CMS\Extbase\Mvc\Controller\ActionController;
@@ -289,8 +290,11 @@ class JoblistController extends ActionController {
 		$site = GeneralUtility::makeInstance(SiteFinder::class)
 			->getSiteByPageId($GLOBALS['TSFE']->id)
 			->getLanguageById($sysLanguageUid);
-		$countryRepository = $this->objectManager->get(CountryRepository::class);
-		$countries = $countryRepository->findAllOrderedByLanguage($site->getTwoLetterIsoCode());
+		$countries = [];
+		if (ExtensionManagementUtility::isLoaded('project_base')) {
+			$countryRepository = $this->objectManager->get(CountryRepository::class);
+			$countries = $countryRepository->findAllOrderedByLanguage($site->getTwoLetterIsoCode());
+		}
 		$this->view->assign('countries', $countries);
 		$this->view->assign('sysLanguageUid', $sysLanguageUid);