Error after Update Event Booking to version 3.12.3

Today I have updated from version 3.12.2 to version 3.12.3 Now I suddenly have texts in english in the frontend again which were all translated already. If I want to edit the languages in the backend now, I get a server error message.
"Forbidden You do not have permission to access this document. „
No matter what I select in the backend for the translations.
What happened there?

Hello

Maybe the language file was broken for some reasons. Could you please submit a support ticket sending us:

- Super admin account
- Link to the page which is having language issue

We are going to check to see what's wrong and get it sorted

Tuan