Solved
STEAM-PC Login Error "We can't log you in" - <RESOLVED!>
- Fresh install of SWTOR on steam - start SWTOR launcher - logged in using free to play account - authentication successful - closed game - start SWTOR launcher - change display name to main prefer...
There will be an option soon to unlink the swtor account see https://help.ea.com/en-us/help/star-wars/star-wars-the-old-republic/swtor-on-steam/
