GitLab on Ubuntu 16.04 LTS - inaccessible repository

Hi, I installed gitlab via APT on Ubuntu 16.04LTS.
However, I have bunch of problems with it now:
-raw file viewer results WSOD
-downloading a repository in zip format results a 0 byte zip file
-downloading a repository in any else format results WSOD

Have you experienced with these issues?
I’m using 3.6.6 of gitlab-shell and 8.13.5 of gitlab with Apache over HTTPS.