TYPO3 Fatal Error: Extension key "" is NOT loaded! when I loaded this Extension

Kuchenbuch reported an issue

In my TYPO3 8.7.2 equal if I loaded with Extension Manager or upload in the ext-Folder. The Extension don#t work.

Reported URL:https://extensions.typo3.org/extension/datec_jobmarket/

User Agent:Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.186 Safari/537.36