Hi @monetenfuchs,
Thanks for reaching out.
Yoast has a global support team, so we can only answer your questions in English. Likely, you were not aware of this when creating your topic. We’d still like to help you as fast as possible; therefore, we’ve used Google Translate.
Regarding your topic:
The server error logs usually provide more details about the issue. If you have access to your server error log, note the date and time before generating the error again. Then, immediately check your server error log for any errors during that period. If you don’t have access to your server error log, please ask your hosting provider to look for you.
If you or your web host cannot pinpoint the cause, please provide us with a copy of the server error log for further investigation. As server logs can cover a significant amount of time, please limit the error log to a few minutes before and after the behavior was reproduced.
If the server error log does not contain any errors at the time of the issue, please enable advanced WordPress debugging with the code here. This code requires that you change line 84 to point to a path on your server. Your web host can provide you with a secure path to save the error.log file.