Cannot assign null to property

Can you perform a git bisect to find the commit that introduced this regression?

I am sorry, I never really worked with git.

Can you get the stack trace please?

The error did not provide a stack trace. Just the given message.
I can send a complete backup of the site before and after he update.

No, thank you. See the site’s logging configuration for getting a stack trace, also called a backtrace.

No code changed in the views module between 10.1.6 and 10.1.7, so I am going to mark this as "Needs steps to reproduce".

Nor the regular sitelog (admin/reports/dblog) nor the site's error.log had a stack trace. So it was hard to find the view causing the error.
Do you know a way to force an error with a stack trace which I can put in public function setOffset()?

Is the website configured to log stack traces? It is that which I was suggesting in comment number six.

I found module Inspect wich can create a backtrace. It is set to 10 levels, but I can expand this. See attachment.

And I found the default Drupal way. See backtrace2.txt

The cause is identical to issue 3361177 🐛 An empty views pager offset field can cause a PHP type error to be triggered. Needs work . After setting offset 0 in the pager, the problem was solved.

Does that mean this issue is a duplicate?

Yes it is a duplicate. This issue is since D10, and issue 3361177 is D11.

Closing this as a duplicate according to #14.