Broken after upgrade

After upgrading with apt from 8.0.1 to 8.2.3-ce.0 a Gitlab installed with the Omnibus package, I get no response when accessing from the local machine (http://localhost:8888/), 8888 is the port configured in /etc/gitlab/gitlab.rb where unicorn is listening to

When reconfiguring, I get the following:

What may all these warnings mean?

/opt/gitlab/bin/gitlab-rake cache:clear --trace

Any idea?
Thank you,