@FrancisCrawford
Would you be able to provide us with the exact error message that pops up?
The error you are getting could be an issue with an add-on. Please try removing your add-ons and see if this same error pops up when you open your crown crate.
For what is worth I add the same issue when I'm removing LUI extended that's work for me. Also having related bug when I'm accepting a gift before.