A helpful user that doesn't have an account on this Jira board just yet (name is Zach McCormick) gave me this feedback on the bug:
It looks like the 1.14.1 changelog says that it introduced a new field
"build context". I figure that they aren't doing a null check when
loading settings, so all jobs that used the commit status setter
before don't have the buildContext field (or whatever it's called) but
the code is trying to access it anyway.
I opened up the job in question on our Jenkins server, clicked
"Advanced", then put a dummy string in then removed it, and saved the
job, and it no longer NPEs on that particular job.
Probably something they should patch in 1.14.2.
I tried to register for the Jenkins issue tracker but they aren't
accepting new users due to anti-spam right now :-/
Figured I'd relay this to you so that you can add some context and a
workaround on the issue