I keep getting this error despite fixing any potential formatting issues. In testing the plugin action works perfectly…it looks like all other plugin action codes that work fine and allow plugin to be published…does anybody have a list of all the different ‘quirks’/bugs in the plugin builder that cause this type of behavior?
I ended up finding a workaround. I created a new plugin, copied the code from the action that wasn’t allowing publishing, then published that new plugin, which worked. After that I attempted to create a new element in my pain plugin that threw the error, and copy the code from now published new plugin, but that still resulted in an error when attempting to publish the main plugin. What finally allowed me to publish my main plugin was copying the element from the published new plugin (which was created by copying the code from main plugin to begin with 
) and pasting that element into my main plugin, and then finally I was able to publish the plugin.
Does anybody know if that work around might have some unintended consequences. Testing it, everything still works as expected. I only assume there may come a time in future if adding attempting to deploy a new version the bug could creep back in.