So, just started the quest to save Darien from Mephala in the Spiral Skein, and I cant use my weapon. LMB works perfectly on any other aspect of the game, checking inventory, clicking on anything in the inventory menu, logging in and out, even other characters in other areas of the game have no problems. All other mouse functions are working. RMB, scroll wheel, even the side buttons, just not the LMB while trying to use my weapon. Mouse also works perfectly out of game.