Errors with NPC stats

I have an NPC party member that is badly bugged and becoming a hindersnce during combat. I have copied event ID where Franz explains the issue. Level 9 Rogue with 18 dex, but the system thinks her dex modifier is -2 or -5. This is also affecting her AC. It should be a 14 but the system and character sheet are only giving her 8 AC. I can not edit this stat.