I've managed to reproduce a bug I kept running into, which causes an assertion failure and then a crash.
I have 2 panes open (let's say, left and right).
My "active" pane is the left one (my cursor is there).
The file that's visible in the right pane (not my active pane) is changed by some external editor.
The next time I move back to the changed file, Sublime correctly notices that it was changed outside and offers to reload it.
When I click "reload", Sublime shows an assertion error, then crashes.
Happened to me for a while before I figured out the exact steps to reproduce.