Sorry to hear it crashed, but hopefully you have source control to roll back to the 4.2.2 version, and if so I'd be tempted to try again.
I managed to migrate my WIP project from 4.2.x to one of the 4.3 betas a couple of months back, which if I recall required a few manual tweaks to get working, but not a lot.
Might be worth posting on the Godot forums to see if anyone else has seen the same issue. Good luck.