I have a project created by UE4.13
Swarm failed to kick off, because something used by another process
I have found that caused the problem is a StaticMeshActor (LightTool) in the scene
if i delete the LightTool , it would be built successfully
After deleting the LightTool Actor i place it into the scene again, it would be built successfully too
But maybe one day or two days later, i reopen the project to build, the problem would appear again
I have only one SwarmAgent.exe running, firewall has been disabled