Debug a bitbucket installation on a local NAS

I'm a freelancing webdeveloper and graphic designer. I'm using Bitbucket, Stash and Confluence on my NAS to manage my projects. Due to a recent OS update on the QNAP NAS my jira is broken in a way that I can't use the UI anymore. Because of that I purchased a new licence (bitbucket now) and installed it on my NAS. Everything seems to work good so far but when I want to push my projects to a new created repository I run into issues like "fatal: unable to access 'MYSERVER/scm/bc/[login to view URL]': The requested URL returned error: 500" I also tried to use SSL but this also doesn't work due to authentification issues. I would like to find a DevOps who has installed bitbucket already in the past and can have a look at my issue via TeamViewer.