We've some jobs which do some generic tasks. On success they are used to trigger some downstream jobs. This is similar to JENKINS-25758, but its resolution didn't help. Downgrade to 1.620 fixed the problem.

There are 2 downstream jobs configured. Starting with 1.621 only the first downstream job gets started after successful build, at best.

Instead of triggering all the downstream jobs they fire this NPE:

Warning: you have no plugins providing access control for builds, so falling back to legacy behavior of permitting any downstream builds to be triggered
Triggering a new build of .....OUR PROJECT NAME...
FATAL: null
java.lang.NullPointerException
at jenkins.triggers.ReverseBuildTrigger.shouldTrigger(ReverseBuildTrigger.java:111)
at jenkins.triggers.ReverseBuildTrigger.access$000(ReverseBuildTrigger.java:84)
at jenkins.triggers.ReverseBuildTrigger$1.shouldTriggerBuild(ReverseBuildTrigger.java:141)
at hudson.tasks.BuildTrigger.execute(BuildTrigger.java:245)
at hudson.model.AbstractBuild$AbstractBuildExecution.cleanUp(AbstractBuild.java:687)
at hudson.model.Build$BuildExecution.cleanUp(Build.java:200)
at hudson.model.Run.execute(Run.java:1788)
at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:43)
at hudson.model.ResourceController.execute(ResourceController.java:98)
at hudson.model.Executor.run(Executor.java:381)