Error 500 for gitlab runners after update from Gitlab CE 12.0.3 -> 12.1.0
After migrating Gitlab 12.0.3 to 12.1. we experience an issue regarding runners.
Runners are stuck and accessing https://gitlab.[redacted]/admin/runners results in an Error 500. The error is persistent even after a restart of gitlab with "gitlab-ctl restart"
Did anyone experience the same issue or is there a mitigation strategy?