Might have created a duplicate of this at: https://issues.jenkins.io/browse/JENKINS-66938

The workaround described there (sending the query manually) makes this plugin usable for one-time configuration.

https://ci.jenkins.io/job/Plugins/job/priority-sorter-plugin/job/PR-88/ provides a prototype of the proposed fix. I'm not comfortable that the proposed fix will resolve the issue in all cases. I'd love to have others review it interactively and through the code.

The bug as reported here was already resolved in release 4.0.0 of the plugin. The failure to provide the "save" button was most likely coming from another plugin in the system that had not yet been updated for configuration form modernization ("tables to divs"). We'll need the list of plugins and their versions where this is failing so that it can be checked with the pre-release build available from https://ci.jenkins.io/job/Plugins/job/priority-sorter-plugin/job/PR-88/

Don't know, if it makes sense, to comment on a closed report....
My safe button is back - using 4.0.0.

But the screen still looks screwed up:

I can send you our list of used plugins and version. Please let me know in this case.
(I don't want to post these permanently on a Web page like that, for security concerns....)

martinjost Please see https://community.jenkins.io/t/migrating-jenkins/894/5 for a list of steps that need to be performed to identify the plugin(s) that are causing the issue. I'm reasonably confident that the issue is not caused by the priority sorter plugin, but by some other plugin that is installed on your system.