Hi all,
I had the same issue and nothing worked for me. but i was finally able to run game after those changes :
turn Game mode off
Run game as Administrator
When I tried after that to turn game mode on or did not run as Admin, game started, but not showed, only sound on background and screen frozen ... I was able to run command line (<Windows key> cmd -> click Run as Administrator) an then alt-tab to this console and write :
tasklist, search for row with Gw2-64.exe <number> and then write taskkill /F /PID <number> and it kills game.
i hope, that patch will be here soon ...