i think i may have found the problem but if it fixes its going to be a pain. i was trying to capture league of legends and 7 days to die. i believe the file was capture graphics hook.ddl or something i cant remember off the top of my head but after a manual uninstall and restart of my system and a re install it worked. i had to to uninstall through controll panel but the file i believe was still holding on. ( re install giving error that the file could not be writen) i haven't had time to try it today or not.
also trying the hotkey method would not work also.
im going to try to stream within the next 30 mins or so and will post a update if it doesnt work i will try the reinstall again hopefully just a random occurrence