UE4.20 Crashing Fatal Error

Building lighting and when it started to import static built lighting it reached 14% and then crashed showing this message below

Fatal error: [File:D:\Build++Portal+Release-Live+Compile\Sync\Engine\Source\Runtime\Core\Private\GenericPlatform\GenericPlatformMemory.cpp] [Line: 179]
Ran out of memory allocating 65536 bytes with alignment 0