The following advice is applicable for self-hosted GitLab instances, but irrelevant for troubleshooting GitLab.com
When you’re getting a 500 error, here are some steps you can take to help troubleshoot the issue:
You can check the logs for errors by running
$ gitlab-ctl tail
and then reproducing the 500 error (visit the 500 error page).
If you look closely, you should find some mention of the 500 error in the error logs. If the problem is not apparent, copy/paste the relevant lines of the error log here and I’d be happy to help make sense of it.
You can also run rake tests to find any issues with your GitLab installation.
$ sudo gitlab-rake gitlab:check --trace
$ sudo gitlab-rake db:migrate:status --trace
These commands will check for a variety of potential problems with your GitLab installation on the application and server level. If anything seems awry, copy/paste the output of these commands and I’d be happy to help diagnose the issue and find a solution.