Can't seem to login into the client (wow.exe)

Hi!

The last time i logged in was 475 days ago. I still can login to the forums with the same details but not into the client (tried e-mail and account name).
I got the 5.4.8 MoP client.

Is this because my in-game account got deleted? (I got a donation account). Or is there an actual way that I can check if my account is deleted?

I am looking forward to a reaction!

Thanks in advance.

- EDIT -

Things I already tried:
1- go to the game folder click on properties and and uncheck read only option ,
2- go to game folder > wtf folder > config.wtf (open in note pad ) > those 2 lines must be stated there :
SET realmlist "logon.warmane.com"
SET patchlist "logon.warmane.com"
3- delete the cache. if the last thing you entered with was game crash
4- Re-installed the complete game



Greetz,
OmeKlaas

Is there any error while you're trying to log, or stuck at "Connected"?

The standard message: "the information you have entered is not valid. Please check you e-mail and/or password blablalba". Nothing more then that.