Software app shows "Unable to get list of updates:" permanently


my software app permanently show this:

I still get install updates via terminal (apt-get update … apt-get upgrade) without any issue.

Does anyone have the same problem and is someone out there who has an idea how to fix this?


So when you run apt update in a terminal, you don’t get any errors? Like absolutely nothing? It all runs and ends without a single complaint?

Normally if you have unmet dependencies it identifies the issue so this is curious.

Did you remove something recently?

I think a was a little bit to hasty while creating this thread. At the end removing an older debian repo (I used it to get Firefox ESR in the past - now it is installed manually - deleted the related files under /etc/apt/sources.list.d/ as well) and removing some other already deactivated repos within the Software app resolved the problem.

Only the original purism, nitrokey and the syncthing repo is configured now.
Now everything works fine again. Updates via Software app as well as via terminal.