Hmmmm. Really weird. I was in a Fleet Action then all of a sudden, the game froze and I got booted. Now I can't log back in. It says I have an invalid username or password.
First, check your caps locks. If it is not where it is supposed to be, then I would check your account info and make sure the game did not shut you off for none payment. Something may have went wrong when the game tried to charge your account. If that does not pan out, then I would contact support and go from there.