Yesterday I was trying to download some stuff off of the exchange, and I had trouble downloading first of all. I had to click it a few times. And then when it came time to install the item, I get an error message saying something about "failed to start game" (Something along those lines). The day before that I installed some stuff from the store but the next day it wasn't working. Is anyone else having this problem?
try deactivating some of the stuff until you find out which it is If it's all of them then they may be corrupted.
Have you patched your game? I know it gives me an attitude if I try to download something when the game isn't patched.
EDIT: I just read your other thread xD Do what is said above then. Or just disable all of the other stuff and try to download the new stuff. If you can, then there's something wrong with your previous downloads.
It decided to start working again. It randomly does this. I don't know why.