Stack trace (just the relevant part):
https://pastebin.com/2A2ndSvs

I added Project EX to "All the Mods 3". I don't know if there is something in project ex's interaction with the other mods, or if this is simply because of the most recent update. Just thought I'd let you know.

Just an update. I've manually rolled back the version to see when it was that it stopped working. It seems to be from the 1.2.0 release onwards (1.1.0.3.4 doesn't have the same crash occurring)