I transfered 4 chars from Cata to Wotlk (3 to account X and 1 to account Y) while 2 out of 3 worked fine on account X the 3rd one had an issue with the name, so i went and proceeded with the race change icon on the character screen so i could change the name and perhaps the race but everything single combination of race and name keeps giving me the "Could not change race for character", i tried searching for the name on the armory to check if anyone had picked the name but i found out that was not the case but the race itself, the 3rd character class was an troll shaman

Now for the account Y problem i followed the same steps and it worked fine, i was able to change the name and the race of the character and was ready to log in but i noticed that the place the character was before i pressed the "Enter World" button was totally blank, it only showed the name of my character , the level and the class but it was like he wasnt allocated to a place yet, i ignored and logged my character, right on the loading screen with the classic "Dwarf on the Gryphon" my game crashed with error. i tried again after deleting the Cache folder with no success, i even tried to Unstuck on the website but it gave me a warning saying my character had nowhere to unstuck to (LOL poor guy), the character class and race before and after the transfer was a tauren druid

Ty for your attention and sorry for the bad grammar and sorry if i posted this on the wrong place