Internal Server Error when updating to PHP 8 (shared hosting)

ℹ️ Support
1

Nextcloud version (eg, 20.0.5): 25.0.2
PHP version (eg, 7.4): 7.4.33

The issue you are facing:
EOL of PHP 7.4, therefor I need to update to PHP 8
When applying in cPanel → PHP selector → 8.0, I get following error on Nextcloud
Internal Server Error
The server encountered an internal error and was unable to complete your request.
Please contact the server administrator if this error reappears multiple times, please include the technical details below in your report.
More details can be found in the server log.

Is this the first time you’ve seen this error? (Y/N):

Steps to replicate it:

  1. cPanel → PHP selector → update to 8.0
2

Did you carefully checked all Moduls? Restart Webserver? Which Webserver?

3

Yes compare all the modules
I can’t restart anyhing, it’s a shared hosting

5

It works now, I activated the moduls:
apcu
zip
mbstring