I’ve seen this warning in prior 5.X versions of Unreal for Mac-
Warning: Failed to build lighting!!! Unreal Lightmass executable is outdated. Recompile UnrealLightmass project with Development configuration in Visual Studio.
Established solves on the forum involve rebuilding it (ref: Unreal Lightmass executable is outdated - #2 by Dariusz1989) . However, this is not functioning for me in 5.6.
I’ve done rebuilding the Lightmass, recompiling engine through Xcode, and trying to build scene lighting to no avail. Is there a step I could possibly be missing?