GitLab install perfectly but next day shows HTTP 500

  • Server: debian jessie 8.7 virtual machine (amd64) running from a windows host (virtualbox).
  • Installed and configured gitlab-ce from repositories (version 9.1.2-ce.0)
    – Using gitlab behind an reverse proxy nginx (i was able to create/invite users)
    – Relevant lines in /etc/gitlab/gitlab.rb:

external_url ‘
gitlab_rails[‘gitlab_email_enabled’] = true
gitlab_rails[‘gitlab_email_from’] = ‘’
gitlab_rails[‘gitlab_email_display_name’] = ‘No Reply (gitlab)’
gitlab_rails[‘gitlab_email_reply_to’] = ‘’

It works like a charm but the next day i get HTTP ERROR 500. The problem seems to be redis inside gitlab container: