[=John Alcatraz;428891]
You ever saw UE4 closing, crash reporter coming up telling you why it crashed, and it magically “came back”? 
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I do, when clicked “Send and restart” 
Probably @ talks about long freezes, which can be confused with a crash. They appeared in 4.10 (at least in my case), sometimes without any reason (non-reproducible) whole editor freezes for 2/3 min, goes back to normal.