I used the Bitnami GitLab (bitnami-gitlab-5.1.0-1-ubuntu-12.04) virtual machine on a Windows 7 Virtual Box and everything worked on until I clicked a file to see its content or clicked the commit id.
Each time I would get a 500 Error, after checking the logs I had this problem: Error: --broken encoding: unknown in views Error: ActionView::Template::Error (could not find any magic files!)
The problem for me was that CharlockHolmes was not installed correctly. The solution was described in https://github.com/gitlabhq/gitlabhq/issues/679#issuecomment-5282141 (please note that the required version for CharlockHolmes as of GitLab 3.1 is 0.6.9)
Just use the find / -name "charlock-holmes*" to find all gems ad folder and delete them.
After that got /opt/bitnami/apps/gitlab/htdocs/ and run the bundle install.
After all is finished just restart the servers: /opt/bitnami/ctlscript.sh restart
Now everything seems to be working fine.