Nostalrius Begins - Quality wow vanilla realm (1.12)

hi i keep having this error on my main.
interface\framexml\mailframe.lua:623;bad argument #1 to 'strupper" (string expected got nil)
its only happening on my main , i already changed the wtf folder from my alts to my main , i already removed all the addons and it still happening. Do u know a solution ? thx

please submit a report on the bugtracker, thank you

Ya. One of the people in your friends list is bugging it out. Delete all of your friends and re-add them.