4.20 Lightmass keeps crashing?

I’ve been trying to bake my lighting but keep getting this error. Have already tried clearing out Swarm and I don’t know where to go from here.

=== Lightmass crashed: ===
Assertion failed: DLLHandle != nullptr [File:D:\Build++UE4\Sync\Engine\Source\Runtime\Core\Private\Internationalization\ICUInternationalization.cpp] [Line: 257]

0x000007fefd4da06d KERNELBASE.dll!UnknownFunction []
0x000007fe95d44a10 UnrealLightmass-ApplicationCore.dll!UnknownFunction []
0x000007fe8514955c UnrealLightmass-Core.dll!UnknownFunction []
0x000007fe850daa4d UnrealLightmass-Core.dll!UnknownFunction []
0x000007fe8503147b UnrealLightmass-Core.dll!UnknownFunction []
0x000007fe850282f7 UnrealLightmass-Core.dll!UnknownFunction []
0x000007fe8501724c UnrealLightmass-Core.dll!UnknownFunction []
0x000007fe8530bc6f UnrealLightmass-Core.dll!UnknownFunction []
0x000007fe850e6641 UnrealLightmass-Core.dll!UnknownFunction []
0x000007fe850ff4d6 UnrealLightmass-Core.dll!UnknownFunction []
0x000007fe8508b36a UnrealLightmass-Core.dll!UnknownFunction []
0x000000013f7177ba UnrealLightmass.exe!FMatrix::InverseFast() []
0x000000013f7809c8 UnrealLightmass.exe!Lightmass::FStaticMeshStaticLightingMesh::Import() []
0x000000013f6db1a5 UnrealLightmass.exe!Lightmass::FLightmassImporter::ImportObjectArray > >() []
0x000000013f70f4c3 UnrealLightmass.exe!Lightmass::FScene::Import() []
0x000000013f6ef709 UnrealLightmass.exe!Lightmass::BuildStaticLighting() []
0x000000013f71a922 UnrealLightmass.exe!Lightmass::LightmassMain() []
0x000000013f73d49a UnrealLightmass.exe!main() []
0x000000013f7c0bdc UnrealLightmass.exe!__scrt_common_main_seh() []
0x00000000772b59cd kernel32.dll!UnknownFunction []
0x00000000774ea561 ntdll.dll!UnknownFunction []

maybe you should rebuild your lightmass.lib?