Fatal error: Uncaught Error: Interface 'TYPO3\CMS\Core\SingletonInterface' not found in /home/.sites/884/site2951/web/test/luger/typo3conf/ext/extension_builder/Classes/Parser/ClassFactory.php:36
Stack trace:
#0 {main}
  thrown in /home/.sites/884/site2951/web/test/luger/typo3conf/ext/extension_builder/Classes/Parser/ClassFactory.php on line 36