Minecraft crashes while streaming to Twitch.tv via Open Broadcaster. The first crash happened after about 20 minutes idling in a single player world, when I right-clicked on a furnace I had just placed. Subsequent crashes happened upon clicking on the Multiplayer button, about 30 seconds to one minute after loading the single player world and walking around, and another time about 30 seconds after loading the single player world and walking around again.

Crashing stopped when I closed Open Broadcaster and repeated the same procedure above; opening a single player world and walking around.