Worked for me with ue4.14! thanks
It worked for me 
Thanks man
This may work for some but I changed the name of my project and now it builds. Weird but hey
Did you keep the project open or do you close the program and then do Build UnrealLightmass or do you pick ReBuild UnrealLightmass?
THIS WORKED FOR ME:
If youâre using 4.10 or later you will need to have the VS2015 dependencies installed.
You can download the Visual Studio Dependencies from Microsoftâs website:
VS2013: http://www.microsoft.com/en-us/download/details.aspx?id=40784
VS2015: Download Visual C++ Redistributable for Visual Studio 2015 from Official Microsoft Download Center
Thanks! That is works)
This is for source build. If youâre using UE4 straight out of GitHub, this is your solution. This does not apply to Epic Games Launcer, I donât think so.
I simply went to my source build directory, and opened the solution. You can read about how to generate the solution file in the UE4 github README:
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Worked here in 4.21.
Thanks!!
Worked for me as well. Thanks a lot
For me the problem was that I had duplicates of some of files (materials, meshes, textures) because I migrated them improperly from other projects. The solution was to delete the duplicates and point to the originals when prompted for replacement in references while deleting the duplicates.
This error happened to me, and I tried all the tricks in the book given here:
Delete derived data cache
Delete meshes
Delete whatevers
Finally I managed to narrow it down to foliage painted on a single landscape tile. It was only certain types of foliage (grass in this instance). I deleted them from the tile, rebuilt the lighting, then repainted them and rebuilt - but this didnât work. So then I remembered I had changed some settings in the foliage type. It originally had Cast Shadow = False, but Cast Dynamic and Cast Static shadow = True, but I had set those two to false for some reason. The latter two options are grayed out when Cast Shadow is set to False, so it shouldnât have mattered. But apparently it doesnât work and the error comes with lighting builds and swarm not kicking off, because after I changed them back to the original settings, I could repaint the grass foliage on the tile and the swarm kicked off.
The strange thing is, that it was only this one tile that gave me this problem. Iâve painted other tiles with this type of foliage before and after I did the checkbox change, and they give me no errors, but it was the only thing I could narrow it down to.
Edit for reference: Iâm running 4.19.3 with vanilla source, a largish level with thousands of foliage actors and 1-2k static meshes.
Just ran into this. It was caused by two different Material Instances have the same GetMaterialHash.
It was fixed by going into one of the material instances and touching a property and resaving.
I found them by debugging, but I think it was outputting it in the editorâs Output Log as well.
For me, the issue seemed to stem from random meshes in the map glitching out. I deleted all of the meshes I had added to the scene since the last lighting build and everything built fine so I narrowed it down further to a single mesh which I simply Cut from the scene and then built all which worked fine so I pasted it back in and built again and problem solved. Be sure to check your map for errors in the message log first and fix those and if that doesnât solve it, try cutting out the most recent meshes since the last build so you can narrow down the problem actor. Also, I strongly recommend using the Save Current As command and appending 02 to the name and use this to find out whatâs wrong. That way you can always go back to the original and copy and paste from there into the new map.
worked for me, UE4.24
thanks!!!
you saved me bruh! many thanks!
TLDR: Move Unreal Engine folder from C drive to desktop / some other file
I had the same issue recently with version 4.25. When you try to build UnrealLightmass, visual studio tries to access a few files located in Engine\Binaries\Win64. One of these files is tbbmalloc. Visual Studio did not have access to this file because my Unreal Engine Source file was in my C drive (C:). As a consequence, Visual Studio couldnât build some of the UE4 Modules and so when I launched the editor, I couldnât build the lighting.
Good, now we know what to do once Unreal ask to build something
Works, thanks!
Still a problem in 2021 - this sorted out one of many problems Iâve come across. Thank you.
Doesnât fix it in my case⌠Any other suggestions please?
Hi .
Currently I used UE4.27 on my project and Iâm facing an annoying problem that is âLighting build failed. Swarm failed to kick off. Compile Unreal Lightmassâ.
From all the tutorials I saw on YouTube, they used Visual Studio 2022 to fix the problem.
Unfortunately, I did not manage to use it. Iâm trying so many time.
My Project file stored in File D. My question is, VS2022 only able to read files stored in C files? What if my project stored in D files, do I need to move it to C file for me to use VS2022.