git push failes with “access denied” error on gitlab 7

When I try to push (from an existing repo) to a new repository on a freshly installed Gitlab CE instance I get an error:

Access Denied.
fatal: The remote end hung up unexpectedly

Strange thing is that pushing actually works for the first repository I created. The second repository gives this error.

I installed Gitlab (gitlab_7.3.2-omnibus-1_amd64.deb) on a fresh DigitalOcean instance (1GB ram) on Debian 7 x64.

An ssh -vT git@[domain] command gives ok: Welcome to GitLab, Ruurd Adema!

When tying to clone the second (empty) repo I get this error:

fatal: '/var/opt/gitlab/git-data/repositories/ruurdadema/encoder.git' does not appear to be a git repository
fatal: The remote end hung up unexpectedly

Checking the repositories folder tells me that the repository isn’t there, but the wiki of the project is indeed there.

I found this error in the log of omnibus 7.4.2:

E, [2014-10-24T21:09:32.502741 #11717] ERROR -- : API call <POST http://127.0.0.1:8080/api/v3/internal/allowed> failed: 500 => <{"message"=>"500 Internal Server Error"}>.

Any ideas of what’s going on?