FP2 won't boot after failed recovery

With your TWRP 3.0.x still working, I guess you don’t have one of the new screens?
(… which normally would require a current TWRP version and you not recovering an older OS version not supporting the new screen yet … but that doesn’t seem to be the problem.)

Well, I’m only good at wiping completely and installing from scratch. That works reliably, but erases all data on the phone. But if you want to try …