Okay, so it's been a while since I last played the game. I opened up the launcher to log in but had no joy. Thought I had forgotten my password so went through the whole reset password business. Still not working. I also use a security key on my phone and that didn't seem to work either, so I went through the process of removing the security key from my account.

Now I'm able to log in to the swtor.com website (obviously as I'm here typing this message) but I still can't log in to the launcher. It keeps saying "The Display Name, Password, or Security Key you have entered is incorrect. Please confirm your login information."

I'm at a loss of what to do now because the login for the launcher should be identical to the site right? Any ideas?

The old launcher may behave like that now , try using this repair utility to ensure you have the latest launcher installed

Other then that ensure launcher.exe is in the exception lists for the antivirus and firewall

ESET disable protocol filtering

Kaperskey disable scan secure/encrypted connections

Nortons (firewall) set to allow instead of auto