Lightning Build Failed. Swarm Failed to Kick off
I looked around the forums at other posts and could not find the right solution.
This problem happened when update 4.7 came and I created a 4.7 version of the project I was working on (my project used to be in 4.6). Ever since then, I have been getting the same error.
I saw a solution on another post that I should find meshes with duplicate names and change them. However I have a lot of different meshes with the same names, does that mean I have to change the names of all these meshes?
asked Mar 27 '15 at 02:09 PM in Rendering
1) Open UE4.sln
2) Build UnrealLightmass
answered May 22 '16 at 10:30 AM
What worked for me was deleting the data cache: C:\Users######l\AppData\Local\UnrealEngine\Common\DerivedDataCache
answered Jan 22 '16 at 11:30 AM
Hey guys! I had this error message and found out the error message was because my C: drive had only 100MB of memory left!
answered May 13 '15 at 08:18 PM
I had this problem as well and would like to add something:
I imported a few static meshes that for some reason didn't automatically add their materials, one mesh had two Material Elements but I left one of them empty since it didn't appear to do anything. And that was what caused the problem, as soon as I added a material to the second Material Element for the Static mesh then light built just fine.
I hope this helps someone!
answered Mar 26 '16 at 10:56 AM
Swarm Agent has a log which spits out an error when you get the "failed to kick off" message in the Editor.
The error is that a file in the Swarm cache being used by another process. Leaving procmon running while starting the build, this is the complete list of processes accessing the file in question:
As you can see, only UE4 itself is accessing the file, not even Windows Defender is causing trouble. Could it be that two threads are trying to create the same file, colliding with each other and keeping Swarm from kicking off?
Sometimes I managed to fix the error by just deleting everything, quitting without saving, and reloading, but not always. The error is very random, and often after hours of trying to track down the object in question using the methods above, it turns out to be an object that baked just fine before.
Apologies for the delay in getting to this one.
There are a couple of reasons that Swarm Failed to kick off.
Some of the more common ones are that the firewall or antivirus may be blocking it from starting properly. You can disable these and then try to build lighting to see if that works.
The other is that there may be multiple swarm agents opened in your take bar (next to your computer clock in the bottom right). When swarm agent is initialized there will be a orange and black S icon that appears. Close any your see here and then try to build lighting.
If none of that works, can you try building lighting in a new template project like the first person or third person templates? This can rule out if it's a project specific problem or swarm agent issue possibly.
answered Apr 09 '15 at 08:48 PM
Tim Hobson ♦♦ STAFF
Swarm will also not work with with source code version of the engine, so if you pulled the source from git and compiled the engine you will either need to use your own solution, or bake the lighting in the launcher engine and then somehow import it over.
answered Oct 14 '15 at 04:24 AM
In my case, it was because a Sphere Reflection Capture was referenced in the level BP !!!
answered May 08 '16 at 02:02 PM
So far deleting the data cache hasn't worked for me. This one level I have has done this twice to me now. Very Annoying. What I did to fix it reasonably quickly was use Shift + click to drag and select half the assets in my level using the Outliner list and copy them and then delete them (without saving of course). Then rebuild the lightmass. If it builds you know its an object in the deleted half of the level. Press Ctrl V to paste the half back. Then copy and delete half of the half you first deleted to continue to narrow it down by process of elimination. Hopefully I an easier process can be found soon.
If you have built UE from source code, you will need to manually copy a DLL file or two. If I remember right its the embree.dll and tbb.dll files. You will have to copy them to your compiled UE location
I just copy them from my UT Editor (launcher installed) location to my development location and this will all ways fix it.
answered Apr 28 '17 at 05:39 AM
THIS WORKED FOR ME:
If you're using 4.10 or later you will need to have the VS2015 dependencies installed. You can download the Visual Studio Dependencies from Microsoft's website:
answered Apr 21 '18 at 12:43 PM
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