It crashed after I created a code block, converted it to a quote block, and the hit ctrl+z to undo (something about a history node not being found, I think. Sorry, should have saved the output).
Sure, just submitted a new issue. Included in the issue, but I think there might be a more general problem with how block conversion is handled (at least for quote and code block types). On firefox at least, it's pretty easy to crash this by messing with block type dropdown.