Open BaseEditor.ini
/Users/Shared/Epic Games/UE_5.1/Engine/Config/BaseEditor.ini
Section
[CookSettings]
MemoryMinFreePhysical=2048
MemoryMinFreeVirtual=2048
Open project logs and find
CookSettings.MemoryMinFreeVirtual: Available virtual memory XMiB less than XMiB
CookSettings.MemoryMinFreePhysical: Available physical memory XMiB less than XMiB
Set correct values for
BaseEditor.ini
[CookSettings]
MemoryMinFreePhysical
MemoryMinFreeVirtual
Optional: force quit unused apps
Done