How to compile lightmass?

[gothicserpent]

@Kontur

Do you build the engine from source? If so, you have to recompile the Lightmass module (as the error suggests).

EDIT:
Open the engine solution in Visual Studio and search for UnrealLightmass, then right click: build.

this worked for me when i had a light build failed to kick off compile light mass error. thank you!