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.