Lighting build failed. Swarm failed to kick off (UE 4.11)

Accel_Sjostrom · April 15, 2016, 12:16pm

Hi!
Whenever i try to build the lights on a level, it fails with the message “Lightning build failed. Swarm failed to kick off”. This constantly happens on all maps (including new levels with no assets).

This problem occured when I upgraded the engine from 4.10 to 4.11.

I have tried all the soloutions in following Wiki Trouble Shooting Guide (A new, community-hosted Unreal Engine Wiki - Announcements - Unreal Engine Forums) but nothing works.

I have also tried with deleting the swarm cache data, but it didn’t help.

Does anyone have any ideas how to fix this?

anonymous_user_4030fea0 · April 15, 2016, 12:33pm

Check the SwarmAgent in your System Tray. Does it report any errors? Last time this happened to me I had to re-install OS from scratch.

undercover · April 18, 2016, 12:41pm

Re-installing the OS sounds kinda overkill. Hopefully there is some other solution.

Accel_Sjostrom · April 18, 2016, 12:45pm

I got the same problem on different computers, so re-install OS is probably not a solution.

anonymous_user_6e7b421a · April 18, 2016, 4:04pm

Could you guys let me know if you are using a source or binary version of the engine? (i.e. built from GitHub or Launcher for Epic Games Launcher)?

Could you also provide me with your ‘dxdiag’ files so I can take a look at your system specs as well?

You might need to rebuild the UnrealLightmass.cpp in ‘Development Editor’ targeted profile within Visual Studio or Xcode, depending on whether you are working on a Mac or PC.

Thanks,

undercover · April 21, 2016, 1:53pm

Hi!
We are using a slightly modified version of the engine were we added some tick groups so hopefully it shouldn’t affect the rendering and light baking system in the engine.

Why do we need to rebuild UnrealLightmass.cpp? According to GIT nothing has changed since we last compiled it.

dxdiag output

anonymous_user_6e7b421a · April 21, 2016, 2:10pm

There is a known issue with UnrealLightmass.cpp needing to be recompiled under development mode. Try it out and let me know if you get the same results, please.

Cheers,

anonymous_user_5948f536 · April 21, 2016, 2:01pm

I am in same team as undercover here is my dxdiag.

link text

anonymous_user_5948f536 · April 21, 2016, 2:13pm

Solved the problem thanks a lot

undercover · April 21, 2016, 2:17pm

Okay, seems like it works now. Thanks a lot!
EDIT: after the rebuild.

Accel_Sjostrom · April 21, 2016, 2:21pm

Rebuilded the Lightmass and now it works. Thank you!

anonymous_user_52e190eb · August 6, 2016, 10:07am

How can i rebuild the UnrealLightmass.cpp in Development Editor. ???

anonymous_user_52e190eb · August 6, 2016, 10:15am

How can i rebuild the UnrealLightmass.cpp in Development Editor. ???

RedStarStudio · September 4, 2016, 9:29am

thank you very much ,it solved my problem.