I agree with @Biologyben. Your X Proximity switch is too high (even though you pushed it all the way up as the instructions told you to do). Mine crashed after upgrading too. So I lowered it to within 1/8" of the end plate and it works fine. [edited to include picture}
As for the “F” connector (Feed Hold), see this thread for info on the correct wiring: PCB Riser Board blocks Feed Hold pins