How to debug 'Cannot connect to the CI server' errors?

GitLab displays Cannot connect to the CI server. Please check your settings and try again. in new merge request headers even though

  1. GitLab CI is properly set up and reports success on commit builds
  2. when pushing new commits to existing merge requests, merge request build info becomes green with expected message CI build passed for 830a9895.

How can I debug this?

No errors appear in either GitLab or GitLab CI production.log files.

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I upgraded to 7.11 Omnibus and am experiencing the same behavior. Any ideas?

Hi Tyler!

See comments in, perhaps the ones by Amias Channer help.

My problem is gone after upgrade to 7.10.4, but I’m not sure if upgrade helped it or was it some other change…