Internal Server Error after Upgrading from 8.2.7.1

After Upgrading to the latest Owncloud 9 it does not work anymore.

I have owncloud installed on http://domain.com directly (not /owncloud).

I read about that problems but nothing of the solution worked for me...
I had some apps that were automatically deactivated while Upgrading.. I also have a custom theme.

Please Help!!!

Please fill out the issue template shown when creating a new thread instead of just deleting it. Furthermore see:

Without all that infos its nearly impossible to help here.

It's not a 500 Internal Server Error with blank page. It is the interneal server error generated by owncloud.

Yes I tried to edit with the template but it does not show up... I'm very sorry.

You still need to provide the matching error from your logfiles to this internal server error. Without it we can close this issue as unsolvable.

It just got the problem.
I did not know where the log file was... Now I saw there was a problem with an app "external"

Now it works!!!

Thanks a lot for this tip!!!!