CI 4.18 -> 4.20 causes RouterException

Only difference.... App is uppercase, and my folder name is app (lowecase).
Can that be the problem?

No.

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Code:

Controller or its method is not found: \App\Controllers\Login::index

This error occurs when the controller class can't be autoloaded.

Did you customize something in autoload configuration?

I can't seem to find anything in the changelog what will cause this behaviour.

Yes, unless there is a bug we don't know, there is no change in that area.

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