Tim Jacomb
added a comment - Actually this was a bug in the tables to divs PR.
Once you saved a tool to the page the page was broken, hadn't been picked up before as loading the initial page is fine...
https://github.com/jenkinsci/jenkins/pull/3895/commits/e335f7b7b9d42b0e03f6598e0b872a7a363e776c
Test now passes, resolving.
Confirmed, ant plugin is broken, this needs changes in the plugin. ATH finally caught an actual error