FTB not recognizing credentials....bought new Flash account yesterday

[EuroNation]

As title says I cannot log into the FTB server, as it says:
Invalid username or password.

• Check your username and password. If you use new mojang account try using email instead of username.
• You need to use paid minecraft account credentials. Mojang account without paid MC won't work.
  
  

Not sure what to do, as I do have a legit account, so please help thank you!