Locks up on Crusade

Okay, so I was testing to see if allowing other factions the ability to Crusade would work. Chapter House, Crusade marker, some units in the unit_prod.txt files... Tried as Sweden, everything seemed as though it was going well. As soon as I dropped the Crusade marker on a province, it told me about the cost to get the Pope to commission it - and I can't remember whether I'd clicked on the tick or not, but it locked up my game. I'm guessing I did something wrong? But what? Any help is greatly appreciated.

EDIT: Crisis averted. You'll never believe this...instead of copying and pasting the modded file, since I had also been looking at an unmodded one for reference/comparison, I copied and pasted that instead. Just tried it with the modded file, and hey presto, a bunch of Order Foot Soldiers appear, no issues...