They updated the "Classic" client on TBC to implement the initial switch to Vanilla to TBC. Then they added "Classic Era" which was a brand new download option and released the update. All characters were copied over to "Classic Era" which means both the "current" version of the character and the "Classic Era" version were removed. Then you needed to decide which one to activate, which would prohibit you of the other (the vast majority of people were able to activate the TBC version).If you want
