[MOP] This account needs to be converted "problem" !

I played WoW Mop - Warmane from a short time but my PC was formated and when i got the game back I tried to log-in with my ACCname and PW but Unfortunately it says "This account needs to converted to a battle.net account. please...
So i started to search on warmane forums and tried every solve for it but it still the same problem.
so please can anybody tell me a final solve for that problem I think i tried everything !!

NOTE : I opened another server and it's worked but i want to play warmane not another one !