I've tried to start the game by using Arc instead of using the launcher that comes with Neverwinter and until the character's selection screen, no problem. But, when I clicked on the button to enter the game, my screen turned black and I was not able to enter the game. Well, it doesn't matter. I asked the question out of…
I had the same problem as hustin1 to kill Prince Sarkon'Iss, having as a companion a Battlefield Medic, being unable to kill the boss. But, I tried again using a Wayward Wizard of rank 25 as a companion and, after an exciting and hard combat, I was able to defeat him.