Basic FleX documentation is :
UnrealEngine\Engine\Source\ThirdParty\FLEX-0.25\doc
and the UE4-specific FleX documentation is :
UnrealEngine\FlexProject\Documentation
Basic FleX documentation is :
UnrealEngine\Engine\Source\ThirdParty\FLEX-0.25\doc
and the UE4-specific FleX documentation is :
UnrealEngine\FlexProject\Documentation