I am currently in the process of trying to install OpenProject on a fresh instance of UCS 5.0 When I run ‘univention-app install openproject’ I get errors looking like this: W: GPG error: https://updates.software-univention.de/4.2/maintained 4.2-5/amd64/ Release: The following signatures couldn't …

The expired UCS keys are re-signed with the UCS5 key. The installation of openproject should work again. For more informations see here ( UCS 4.x key expired )