Did you create your server account on t3aonline.net?
I created my Revora Account.
"In order to use T3A:Online, you need to register a Revora Account.
If you already have an account from the Revora Forums you can skip this step and log in to set up your T3A:Online server login."
Then I try to log in with my Revora Account and the message that i showed you ("The username or password supplied is not valid.") appears.