i have been having this same problem. all other tabs work but when i go to gem store, screen goes black, sound is still there but black. i hit cntrl-alt-del to bring up task manager then in process of it coming up screen comes back, but if i click on anything on screen it goes black and have to repeat the cntrl-alt-del process to bring it back. cant be graphics driver because i just updated it a couple of days ago because of a crashing issue with another game after they did a update. and all other windows updates are current. been having this problem since i can remember starting gw2 2 years ago. also as some other posted. there is no problem with clicking things on screen and blacking out after i restart game. i also did the temp folder cleaning also still a problem.