@infograf768 we moved com_config to the (legacy) MVC (which changed folder names for example from model to Model and brought the old models folder back). What OS are you using?

hmm.
We have an issue here. It seems that on Macintosh, both Model and model are not fetched by Eclipse.
Therefore I get only model

Currently in 4.0-dev, for whatever reason, com_config has both a model and Model folder. See https://github.com/joomla/joomla-cms/tree/4.0-dev/administrator/components/com_config

That will certainly not work for Windows machines as Windows doesn't make a difference between uppercased and lowercased folders.

You can put the PHP classes into a src folder (i know some people don't like it) then it will work and you will become upgrade safe. I guess the upgrade from 3 to 4 will also not work on Windows for com_config.
Thats the challenge every component faces when it get changed to namespaces.

Thats the challenge every component faces when it get changed to namespaces.

Only when they followed the "new MVC" like com_config. The classic MVC used different folder names and there will be no issues when going to namespaces. So yes, we will need some special workaround like moving the classes to "src" for com_config (which we hopefully can revert in a later release) due to that.

#16700 should fix this @infograf768 please test :-)

Yes I meant new MVC.