Throwing null pointer exception when we click login with the following settings.
Jenkins Version: 2.195 (Tried different Jenkins Versions, same issue) jobConfigHistory: 2.23.1
Looks like this change [1] is causing the issue.
[1] https://github.com/jenkinsci/jobConfigHistory-plugin/compare/jobConfigHistory-2.23...jobConfigHistory-2.23.1?expand=1
For more details: https://gist.github.com/nrayapati/ab1d246e1ae8491163a7a545f7f05ad6
Somehow this got resolved with the latest upgrade, which has pulled in few other plugins (I am guessing a git-client plugin could have resolved the issue)
Please try the newest plugin version and be sure, that you've write and directory create rights to the directory where you save the history.
Version 2.23 saves histories not correctly, that's maybe the reason why you think it works.