Same problem here, I even deactivated ALL of the transitions I made myself. Using a 15" late 2013 Macbook Pro 2.3 GHZ Intel Core I7 16GB of RAM & 2GB VRAM Last night it froze & I had to force quit. Transitions are set to random. The next transition was "Flash" Playing HD file from Smash Vidz (which I've never had problems with before) I believe Callen spoke to you about problems with transitions I've made, but this problem is happening even with some stock ME transitions.