How to reproduce:
1. Open the attached Unity project.
2. Open the "mixed_world_Nov-21-232730-2017_Apr-22-154518-2018.unity" scene.

Expected result: The scene loads and opens.
Actual result: Unity crashes. Sometimes, the computer freezes instead.

Reproducible with - 2017.1.5f1, 2017.2.3p2, 2017.4.7f1, 2018.1.9f1, 2018.2.0f2, 2018.3.0a5

Note:
If the computer crashes, these lines are written in the Editor.log:

DynamicHeapAllocator allocation probe 1 failed - Could not get memory for large allocation 50331648.
DynamicHeapAllocator allocation probe 2 failed - Could not get memory for large allocation 50331648.
DynamicHeapAllocator allocation probe 3 failed - Could not get memory for large allocation 50331648.
DynamicHeapAllocator allocation probe 4 failed - Could not get memory for large allocation 50331648.
DynamicHeapAllocator out of memory - Could not get memory for large allocation 50331648!
Could not allocate memory: System out of memory!
Trying to allocate: 50331648B with 16 alignment. MemoryLabel: Yaml
Allocation happend at: Line:19 in C:\buildslave\unity\build\Runtime/Serialize/TransferFunctions/YAMLMemory.cpp