I found the problem in the log. I’m not sure if it’s my own memory limitation (I have 16GB RAM) or a memory management bug in UE4:
[2020.12.07-17.02.44:107][966]LogMemory: Warning: Freeing 33554432 bytes from backup pool to handle out of memory.
[2020.12.07-17.02.44:118][966]LogMemory: Warning: MemoryStats:
AvailablePhysical 572383232
AvailableVirtual 69783552
UsedPhysical 11002134528
PeakUsedPhysical 12108525568
UsedVirtual 38617370624
PeakUsedVirtual 38695047168
[2020.12.07-17.02.44:118][966]Allocator Stats for TBB: (not implemented)
[2020.12.07-17.02.44:121][966]LogOutputDevice: Warning:
Script Stack (0 frames):
[2020.12.07-17.02.44:123][966]LogWindows: Windows GetLastError: The operation completed successfully. (0)
[2020.12.07-17.02.47:431][966]LogWindows: Warning: SymLoadModuleExW. Error: 8
...
[2020.12.07-17.02.47:435][966]LogWindows: Error: === Critical error: ===
[2020.12.07-17.02.47:435][966]LogWindows: Error:
[2020.12.07-17.02.47:435][966]LogWindows: Error: Fatal error: [File:D:/Build/++UE4/Sync/Engine/Source/Runtime/Core/Private/GenericPlatform/GenericPlatformMemory.cpp] [Line: 197]
[2020.12.07-17.02.47:435][966]LogWindows: Error: Ran out of memory allocating 74520768 bytes with alignment 0
[2020.12.07-17.02.47:435][966]LogWindows: Error:
[2020.12.07-17.02.47:435][966]LogWindows: Error:
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffd11e23e49 KERNELBASE.dll!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffc9e5dc386 UE4Editor-Core.dll!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffc9e5dfae8 UE4Editor-Core.dll!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffc9e2edd5d UE4Editor-Core.dll!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffc9e0f0c8a UE4Editor-Core.dll!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffc9e193a56 UE4Editor-Core.dll!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffc9e193b93 UE4Editor-Core.dll!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffc88c74c38 UE4Editor-GPULightmass.dll!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffc88c1c33a UE4Editor-GPULightmass.dll!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffc88c0530c UE4Editor-GPULightmass.dll!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffc88c0f505 UE4Editor-GPULightmass.dll!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffc88c22a2d UE4Editor-GPULightmass.dll!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ff6c43a9b6a UE4Editor.exe!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ff6c43c113c UE4Editor.exe!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ff6c43c121a UE4Editor.exe!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ff6c43d527d UE4Editor.exe!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ff6c43d7faa UE4Editor.exe!__scrt_common_main_seh() [d:\agent\_work\5\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffd13927034 KERNEL32.DLL!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffd1455cec1 ntdll.dll!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error:
[2020.12.07-17.02.47:463][966]LogExit: Executing StaticShutdownAfterError
[2020.12.07-17.02.47:964][966]LogWindows: FPlatformMisc::RequestExit(1)
[2020.12.07-17.02.47:964][966]LogCore: Engine exit requested (reason: Win RequestExit)
[2020.12.07-17.02.47:972][966]Log file closed, 12/07/20 12:02:47