Forum account is not used to log into the game (most common reason for this error)
In the
Setup Guide under step 2, if you follow through this section there is a link that'll have you setup a Loginserver account and thats what you use to log into the game
Small side notes: You can skip the account linking part if you dont have accounts already with eqemulator and if you setup an SMS, it is locked to that number forever. This can never be changed. If your number ever changes this ability is lost forever. SMS can also be skipped if you choose so