Just a quick addendum due to the fact that I'm not sure if this is related to Raedric's Hold or a specific item that I am now avoiding.
I found a ring on the Siege Platform, in the Hold, which granted the ability "Combusting Wounds".
I found that equipping it to a character, picking the item up and not equipping it, or placing it directly into the stash all caused a black screen upon zoning. I can, however, enter the siege platform and loot everything EXCEPT for that ring, and I don't run into any difficulties.
It seems that this item (which grants a skill/spell) is bugged similarly to the priest robe disguises.