Byg's Grim Reality IV Specific Bugs:
BUG #1: Scutage Tax CTD thread here
BUG #2: Start-of-game agents all have supply traits (i.e. 100% Army Supplies - though they don't increase/decrease each turn). Recruited agents seem unaffected, but agents granted at game start (checked spy, diplomat, merchant, cardinal) have the traits.
SCREENSHOTS
Accuracy Issues:
ISSUE #1: Bohemond di Taranto was the Prince of Antioch during 1100 A.D. after the First Crusade, I can't find any sources to suggest he was associated with Edessa, yet he is now the governer of Edessa in The Crusader States' early era campaign in 6.3, whereas in 6.2 + RR/RC he was correctly the governer of Antioch.
SCREENSHOT