"Undefined" pop-up when editing a project with a long species list

I forgot about this issue and added too many requirements to a project again - has anyone found a way to successfully remove things and make their projects usable again? Last time I ended up just deleting the whole thing and manually re-doing it with fewer requirements, but that was a pain.

I’ve seen the mentions about trying API, but I’ll be honest, I barely know what that is, much less how to do anything with it.