In a powered cube game, my opponent activated Memory Jar while we both had a copy of Sheoldred the Apocalypse in play, which put 28 triggers on the stack.

At this point, the game lagged badly. I attempted to cast Swords to Plowshares, but it would not allow me to select a target. One screenshot shows it on the stack with no targets. I attempted to cancel and recast it a couple times, at which point the game fully stopped responding and I tried to restart the client, and presumably timed out.