[5e OGL] Weirdness with the character sheet

In my game I'm encountering some really weird things with my players AC. One player's AC with Dexterity 16 and Studded Leather equipped from the compendium some how has an AC of 27. I've checked all of his gear for mods and his setting for changes and nothing seems to be out of place. This prompted me to check the other characters and the barbarians custom AC seems to be fine, but the other two characters that wear normal armor it seems to have no effect to load it from the compendium. Whatever their AC value is seems to have been rendered static. I then loaded a new character to test with and everything seems to be in working order with a fresh sheet.  It's very strange. Does anyone have a suggestion to fix this without making my players copy all their information into new sheet?

It sounds like your player has an extra +12 to their AC from somewhere. On the Attributes & Abilities Tab of his Character, try to locate and delete all Attributes named 'globalacmod'. To delete an Attribute, hover over it and press the x button that appears.

I had a similar situation with one of my players as well. For some reason, the players staff was giving him a +10 to ac. I resolved it by deleting the item and re-adding the item. Unfortunately in order to find out what was causing the error, I had to remove each item one by one.