We have one project configured as multibranch pipeline project with branch filtered master and development. After few hours the master branch is disabled with a strikethrough symbol across its name and build option not available .
When clicked on "Scan Multibranch Pipeline", it enabled the branch and pipeline logs show "Branch ReOpened".
Initially we assumed it would be because of Option "Exclude branches included in pull request" but enabling "All branches" too is disabling the master branch time and time again.
Pipeline Logs are not providing any clear indication of whats happening causing it to disable .Please help .
This looks like a bug to me. First I'll go to http://[jenkins]/log/all to see if there are any interesting logs there, then I would open an issue on https://issues.jenkins.io/secure/Dashboard.jspa
Also this issue might be happening after a recent upgrade of jenkins plugins or jenkins itself, I would downgrade everything to try to get my jenkins back to the way it was, then upgrade the plugins one by one or few by few to try to isolate what is causing the issue.
Finally, if you have jobdsl scripts, I would check these scripts to see if there is not a script that when executed is recreating the job and overrides the disabled status