Can't reorll to alliance

Hey.i can't reroll.When I try to change a faction, I get an error - That character does not exist or does not belong to your account.
Someone know how to fix it?

you need to create an ally level 1 with same class to be able to move your Horde characters to Ally.
Why? so the system will give you the same appearance of the lvl 1 character

thanks,now it works!

So if i make same class lvl 1 in ally, will my transfered char have his old name, name of the lvl1 ally or i get to choose a new name???

You will have your old name.