For me, the issue began just updating to 15.1. Both Giga and Photo AI are either crashing Photoshop or producing a corrupted file. I’ve never had a dot 1 update screw things up. Ugh! It was silly of me not to check beforehand, but now I’m in a bind…
After restarting my machine, the stand-alone versions started working, and then the plugin mysteriously started working again. I have no idea why or if this will hold.