Leathal Error while loading into Dalaran

On one of my characters, my only 80 and guild master of my guild, I am receiving lethal errors while on the loading screen logging into Dalaran. This occurs on no other characters, and always in the same place on the loading screen (about 80% of the way finished). The error reads:

Failed to read file WORLD\GENERIC\ORC\PASSIVE DOODADS\BANNERS\CLANBANNER06.blp.

I've submitted a ticket, but do not know how long the response will take, and hope that there will be a quicker fix here. As it stands I am completely locked out of this character.

I received a response from a GM just now, saying "An issue from your ticket was taken care of."

I attempted to log into my character in Dalaran and was met with the same lethal error.

I was able to fix the issue by deleted my Cache folder, although have not heard back from my follow-up ticket saying that it still wasn't fixed.