WorldInfo_0 needs rebuilt lighting.

Switched to Unreal 4.10 Preview, opened my project, it asked to make a copy, I did. I renamed the folder/project to get rid of the external reference error, built the lighting and what do you know, no more error.

Indeed 4.9 is bugged.

When I use a Landscape Grass Layer with any static mesh, I receive this error. I have tried everything, no matter what I try, using Landscape Grass Layer causes this map build error. There are posts about this with information on how to actually solve the error, yet I have tried all of the suggestions numerous times to no avail.

I cannot solve this error alone, I’m using the exact simple setup here,

I believe this is a bug in the engine due to the fact it only happens when i use Landscape Grass Layer. Can I get a definitive answer here? I’ve read forum posts back from August 2014 with the same problem unanswered.