No access to the admin area after activating full text search

When I activate the Full text Search app, I can no longer access the admin area, and I get the following error message in the logs:

fehlerindexexception: Class "OCA\FullTextSearch\AppInfo\Application" not found in file '/var/www/nextcloud/apps/fulltextsearch/lib/Settings/AdminSection.php' line 68/var/www/nextcloud/lib/private/AppFramework/App.php - line 183:OC\AppFramework\Http\Dispatcher->dispatch()/var/www/nextcloud/lib/private/Route/Router.php - line 315:OC\AppFramework\App::main()/var/www/nextcloud/lib/base.php - line 1056:OC\Route\Router->match()/var/www/nextcloud/index.php - line 36:OC::handleRequest()Verursacht durch Error: Class "OCA\FullTextSearch\AppInfo\Application" not found/var/www/nextcloud/lib/private/Settings/Manager.php - line 136:OCA\FullTextSearch\Settings\AdminSection->getID()/var/www/nextcloud/lib/private/Settings/Manager.php - line 242:OC\Settings\Manager->getSections()/var/www/nextcloud/apps/settings/lib/Controller/CommonSettingsTrait.php - line 116:OC\Settings\Manager->getAdminSections()/var/www/nextcloud/apps/settings/lib/Controller/CommonSettingsTrait.php - line 67:OCA\Settings\Controller\AdminSettingsController->formatAdminSections()/var/www/nextcloud/apps/settings/lib/Controller/CommonSettingsTrait.php - line 148:OCA\Settings\Controller\AdminSettingsController->getNavigationParameters()/var/www/nextcloud/apps/settings/lib/Controller/AdminSettingsController.php - line 68:OCA\Settings\Controller\AdminSettingsController->getIndexResponse()/var/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php - line 230:OCA\Settings\Controller\AdminSettingsController->index()/var/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php - line 137:OC\AppFramework\Http\Dispatcher->executeController()/var/www/nextcloud/lib/private/AppFramework/App.php - line 183:OC\AppFramework\Http\Dispatcher->dispatch()/var/www/nextcloud/lib/private/Route/Router.php - line 315:OC\AppFramework\App::main()/var/www/nextcloud/lib/base.php - line 1056:OC\Route\Router->match()/var/www/nextcloud/index.php - line 36:OC::handleRequest()

Nextcloud Hub 4 (26.0.1)
PHP 8.1.18

Does anyone have any idea why this might be

Thank you for your help
Alex

Start in apps/fulltextsearch/lib/Settings/AdminSection.php at line 68 and inspect how the admin section identifies the application. Reproduce the admin-area failure with Full text Search activated, then verify that the admin area loads without the reported missing-class error.