Please remove the bug report from this post. It has nothing to do with it. Look at the crash log; Assertion failed: IsRotationNormalized() ; The crash is clearly shown to be different in the thread Assertion failed: (void)((∈Data[InstanceIndex]) + 1) <= (void*)(InstanceOriginDataPtr + CurrentSize) . I’ve fixed the one in the bug report but the one in the thread is much more severe and undecipherable but anyone who didn’t write it.
I made a forum thread here: Engine bug related to HISM / Foliage Spawners causing map/tile corruption - Engine Source & GitHub - Unreal Engine Forums