Strange, seemingly random crash

Hi, I get this same crash every couple minutes and I have no idea what it means.

Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:/Users/build/Build/++UE4/Sync/Engine/Source/Runtime/Core/Public/Containers/Array.h] [Line: 611]

It doesn’t happen at any specific time, but it seems to occur randomly. Here’s the full log:

Thanks!

I am getting this too. Does anyone have any solutions on this?