I'm having the same problem here and it started yesterday a few hours after reset (Like 4 hours after it). The rest of the day I was able to use the BLTP without any problems. But the problem is with the gem tab. I can open the BLTP using the npcs, but if I select the gem tab... insta crash. Tried everything from clearing cache to repair the game... nothing seems to change/help. So, ANET, how can I fix this problem and spend my gems? xD