My unreal engine has randomly been freezing the last hour. Besides deleting elements one by one in the culprit level. Is there anyway to find out whats freezing my engine? If i click play, it randomly it freezes the engine and I have to end task it, it shoots up to 4gigs (takes my computer to 90-95% of ram memory, i have only 8 gigs) of ram and becomes unclickable forever till I end task.
I seem to have a similar problem.
Whenever I try to find out, whatever creates the freeze, I try to use logs, so I can see them in the Output Log while I am playing in Editor. But I cannot be really sure, if this is the correct last line, and if it is, it seems strange for freezing while computing another FVector direction. So I think the Log is delayed, while the code gets stuck somewhere later.
The .log file under \Saved\Logs\ are shorter with missing some lines, which were displayed on the Console Output Log, though.
If someone can help out, it would be really great.
I am using Unreal Engine 4.11.2 currently and am solely programming in C++.
Kind regards.
Hey, I might have found an answer to your question.
I had a similar problem, as I wrote above.
What I did to get to the bottom of this problem was to… well… let Unreal take up all of my RAM and let Windows expand all additional Memory onto the hard disk drive. It took over 40 minutes of not being able to use the pc at all, as the RAM was full and the HDD did a lot of work. But eventually UE crashed with “Ran out of memory allocating 6100687824 bytes with alignment 0” and the last lines of my problem inside the code.
What I wished for is being able to reduce the maximum amount of RAM, UE4 can use up until it will crash as it has used up all of the allowed memory. That way we could stop UE taking all of the ressources and leaving the user with nothing left behind, so we could still use our PC.
Maybe this might help you. Be patient or do something else apart from using the PC. For me this worked out and I can finally fix my problem. 
Kind regards.