Upgrade upgrade to 5.0 appears to hang

Upgrading 4.4-8 errata 1118 to 5.0 seems to hang in the upgrade process.

This was launched from the GUI and the logs are repeating.

Starting univention-upgrade. Current UCS version is 4.4-8 errata1118

Checking for package updates: none
Checking for app updates: none
Checking for release updates: 5.0-0
Please rerun command without --check argument to install.

Any suggestions for next steps?

Is this related to the 4.x apt key expiration (link) or did the updated eratta fix this issue?