Login unavailable after creating custom field on group

Infos:

  • Used Zammad version: 3.3.0
  • Used Zammad installation source: package
  • Operating system: Ubuntu 18.04.4
  • Browser + version: Chrome 71.0.3578.98, Chromium 80.0.3987.87, Firefox 74.0

Expected behavior:

  • after creating custom field for group objects, agents can login with there credentials

Actual behavior:

  • agents cannot log in at any time
  • The following error is displayed: “CSRF token verification failed!”

Steps to reproduce the behavior: