unable to create plugin Run Configuration in existing project

I had been developing a plugin across a few days in 2024.1.4 using devkit-241.18034.69, able to successfully build and run it using the Gradle Run Plugin run configuration. This is openjdk  21.

My machine (running MacOS Sonoma 14.5) and thus IDEA crashed.

On restarting the IDE, the run configuration to execute my plugin had disappeared. Any attempts to add a new run configuration are ignored--when I click on:
   File → Edit Configurations → + → Plugin
… nothing whatsoever happens.

I tried invalidating the caches, restarting, reinstalling IDEA, reopening the project, blowing away the .IDEA directory.

If I create a new plugin, it does create a run configuration and  I'm able to execute it successfully. However, clicking on the + button to add a second plugin run configuration similarly one doesn't work. Maybe it never did. (Maybe it only lets you create one, and IDEA still thinks there's one in my project?)

What's the easiest way to re-add a plugin run configuration to my project?

thanks in advance!