I installed (without Galaxy) the current version of the game 1.26 without any problems and it works. But as soon as I had install one of my DLC I get the message *plugin googlepad failed to load* see attachment. After that the game does not start and I have to deinstall / install totally new. Please help. Thanks!

hmm, the error is clear; your googlepad installation is not working.
I did a quick search on the net for 'Plugin Googlepad failed to load because module googlepad was not found'.
This produced several results like an unrelated but still interesting result at the unreal forum:
https://forums.unrealengine.com/t/plugin-failed-to-load-because-module-could-not-be-found/472360
Then there was another that addresses the same issue, but this is a programmer:
https://stackoverflow.com/questions/69386171/gradle-build-failure-when-packaging-googlepad-asset-packs-in-unreal-engine

Long story short, either uninstall the googlepad software properly or repair the installation :)

Thanks for your response. In fact, I reinstalled the game three times to figure out which of the DLCs was causing the error message. The error happened every time. I got a bit frustrated and played something else for a while. Luckily, the following update (1.26d) worked normally again, and I was able to install all three of my DLCs without any issues. I also found it strange that apparently only I got this error message (couldn't find anything online about it either). Maybe it also has something to do with my Windows 11 installation, which is a bit quirky oO. But now everything's fine, and the hunt can continue (the game has become one of my top 5 in the meantime). so happy hunting to all :D