A few things you can do if you cannot log in:
1. Try retyping it, incase you made an error.
2. Make sure that Caps Lock is off!
3. Make sure that if your username has any numbers to write them using the numbers above the keyboard, not the numpad.
4. If your username is longer than 16 characters or has strange symbols, you will have to make a new account. Registration is open right now, so you'll just have to hurry in to make a new account!
Hope this helps! ^^
