Having issues on MoP

I'm sure there is a better place to post this but still, it has to do with MoP so I figured I'd ask here. I can't seem to log in for some odd reason. Everything was working fine last night when I was on and now I cannot connect at all. I keep getting this message

"This account needs to be converted to a Battle.net account. Please [Click here] or go to: [http://eu.battle.net/account/creation/landing.xml] to begin the conversion."

Is there anyone else having this issue or have had it? lf so, how do I fix it? Thanks :)

check your realmlist