Lightmass/texture issues after build. crashing!

Good morning guys.
I am building a kinda open world game (city). And after I populated the scene/map with more details I ran into issues when building.
I really hope someone can help me figure out what I am doing wrong.
In the beginning of my build issues, it would stop and alert me to error and warnings.
Some of them I understood such as overlapping UV’s? Which I addressed. Others were certain foliage meshes were not set to Dynamic shadows/lighting.
I also went and swapped out 8k megascan surface textures to 2k of the same.
This was the initial error log I would get:

=== Lightmass crashed: ===
Fatal error: [File:D:/Build/++UE4/Sync/Engine/Source/Programs/UnrealLightmass/Private/Lighting/LightingSystem.cpp] [Line: 1458]
Static lighting thread exception:
Fatal error: [File:D:/Build/++UE4/Sync/Engine/Source/Runtime/Core/Private/GenericPlatform/GenericPlatformMemory.cpp] [Line: 197]
Ran out of memory allocating 150405696 bytes with alignment 0
0x00007ffcefe8a218 UnrealLightmass-Core.dll!UnknownFunction []
0x00007ffceff08bd6 UnrealLightmass-Core.dll!UnknownFunction []
0x00007ff78b4d0ab8 UnrealLightmass.exe!TArray<Lightmass::FTexelToVertex,TSizedDefaultAllocator<32> >::ResizeGrow() []
0x00007ff78b4f26b9 UnrealLightmass.exe!Lightmass::FStaticLightingSystem::ProcessTextureMapping() []
0x00007ff78b4d8eb4 UnrealLightmass.exe!Lightmass::FStaticLightingSystem::ThreadLoop() []
0x00007ff78b4d41b3 UnrealLightmass.exe!Lightmass::FMappingProcessingThreadRunnable::Run() []
0x00007ffcf029d547 UnrealLightmass-Core.dll!UnknownFunction []
0x00007ffcf02967c0 UnrealLightmass-Core.dll!UnknownFunction []
0x00007ffd8b727034 KERNEL32.DLL!UnknownFunction []
0x00007ffd8d1c2651 ntdll.dll!UnknownFunction []

0x00007ffd8ae34b89 KERNELBASE.dll!UnknownFunction []
0x00007ffcf0282d56 UnrealLightmass-Core.dll!UnknownFunction []
0x00007ffcf0286407 UnrealLightmass-Core.dll!UnknownFunction []
0x00007ffcf0047b1d UnrealLightmass-Core.dll!UnknownFunction []
0x00007ffcefe8a240 UnrealLightmass-Core.dll!UnknownFunction []
0x00007ffceff08bd6 UnrealLightmass-Core.dll!UnknownFunction []
0x00007ff78b4d0ab8 UnrealLightmass.exe!TArray<Lightmass::FTexelToVertex,TSizedDefaultAllocator<32> >::ResizeGrow() []
0x00007ff78b4f26b9 UnrealLightmass.exe!Lightmass::FStaticLightingSystem::ProcessTextureMapping() []
0x00007ff78b4d8eb4 UnrealLightmass.exe!Lightmass::FStaticLightingSystem::ThreadLoop() []
0x00007ff78b4d41b3 UnrealLightmass.exe!Lightmass::FMappingProcessingThreadRunnable::Run() []
0x00007ffcf029d547 UnrealLightmass-Core.dll!UnknownFunction []
0x00007ffcf02967c0 UnrealLightmass-Core.dll!UnknownFunction []
0x00007ffd8b727034 KERNEL32.DLL!UnknownFunction []
0x00007ffd8d1c2651 ntdll.dll!UnknownFunction []

0x00007ff78b4c8966 UnrealLightmass.exe!Lightmass::FStaticLightingSystem::MultithreadProcess() []
0x00007ff78b497c04 UnrealLightmass.exe!Lightmass::FStaticLightingSystem::FStaticLightingSystem() []
0x00007ff78b44a339 UnrealLightmass.exe!Lightmass::BuildStaticLighting() []
0x00007ff78b470d57 UnrealLightmass.exe!Lightmass::LightmassMain() []
0x00007ff78b48fdc3 UnrealLightmass.exe!main() []
0x00007ff78b4f88b4 UnrealLightmass.exe!__scrt_common_main_seh() []
0x00007ffd8b727034 KERNEL32.DLL!UnknownFunction []
0x00007ffd8d1c2651 ntdll.dll!UnknownFunction []

However, ever since I swapped out 8k megascans to 2k megascans surfaces, and removed a mesh with no lightmap uv, it now will build lighting to 100%, and then when it goes to the next stage (importing,/exporting light maybe??) the program crashes entirely and closes leaving me no type of log or reason.

EDIT- So, it reaches around 47% of Encoding Textures/encoding lightmaps and boom. Porgram crashes and shuts off.

Below are my computer specs, and below them is a couple of screen grabs of the world outliner which shows the lighting actors I have in place.
Does anybody have any idea where I am going wrong with this? Thanks very much.



After more research I went in and compressed some textures that are 4k down to 2k. Went to press build and got the following error map check:

=== Lightmass crashed: ===Unhandled Exception: EXCEPTION_ACCESS_VIOLATION writing address 0x0000000000000000
Fatal error: [File:D:/Build/++UE4/Sync/Engine/Source/Programs/UnrealLightmass/Private/Lighting/LightingSystem.cpp] [Line: 1458]
Static lighting thread exception:
Fatal error: [File:D:/Build/++UE4/Sync/Engine/Source/Runtime/Core/Private/GenericPlatform/GenericPlatformMemory.cpp] [Line: 197]
Ran out of memory allocating 217252672 bytes with alignment 0
0x00007ffccd12a218 UnrealLightmass-Core.dll!UnknownFunction []
0x00007ffccd1a8bd6 UnrealLightmass-Core.dll!UnknownFunction []
0x00007ff7a1b94bea UnrealLightmass.exe!TArray<Lightmass::FGatheredLightMapSample,TSizedDefaultAllocator<32> >::ResizeTo() []
0x00007ff7a1b925d4 UnrealLightmass.exe!Lightmass::FStaticLightingSystem::ProcessTextureMapping() []
0x00007ff7a1b78eb4 UnrealLightmass.exe!Lightmass::FStaticLightingSystem::ThreadLoop() []
0x00007ff7a1b741b3 UnrealLightmass.exe!Lightmass::FMappingProcessingThreadRunnable::Run() []
0x00007ffccd53d547 UnrealLightmass-Core.dll!UnknownFunction []
0x00007ffccd5367c0 UnrealLightmass-Core.dll!UnknownFunction []
0x00007ffd73777034 KERNEL32.DLL!UnknownFunction []
0x00007ffd741e2651 ntdll.dll!UnknownFunction []

Unhandled Exception: EXCEPTION_ACCESS_VIOLATION writing address 0x0000000000000000

0x00007ffd58c616e9 VCRUNTIME140.dll!UnknownFunction []
0x00007ff7a1b926cf UnrealLightmass.exe!Lightmass::FStaticLightingSystem::ProcessTextureMapping() []
0x00007ff7a1b78eb4 UnrealLightmass.exe!Lightmass::FStaticLightingSystem::ThreadLoop() []
0x00007ff7a1b741b3 UnrealLightmass.exe!Lightmass::FMappingProcessingThreadRunnable::Run() []
0x00007ffccd53d547 UnrealLightmass-Core.dll!UnknownFunction []
0x00007ffccd5367c0 UnrealLightmass-Core.dll!UnknownFunction []
0x00007ffd73777034 KERNEL32.DLL!UnknownFunction []
0x00007ffd741e2651 ntdll.dll!UnknownFunction []

0x00007ff7a1b68966 UnrealLightmass.exe!Lightmass::FStaticLightingSystem::MultithreadProcess() []
0x00007ff7a1b37c04 UnrealLightmass.exe!Lightmass::FStaticLightingSystem::FStaticLightingSystem() []
0x00007ff7a1aea339 UnrealLightmass.exe!Lightmass::BuildStaticLighting() []
0x00007ff7a1b10d57 UnrealLightmass.exe!Lightmass::LightmassMain() []
0x00007ff7a1b2fdc3 UnrealLightmass.exe!main() []
0x00007ff7a1b988b4 UnrealLightmass.exe!__scrt_common_main_seh() []
0x00007ffd73777034 KERNEL32.DLL!UnknownFunction []
0x00007ffd741e2651 ntdll.dll!UnknownFunction []

If anybody has some understanding of what this means id greatly appreciate it. I will continue to try to research this but hoping someone with experience might give me a pointer as to how I can fix this!