Unreal 4.9.2 Lighting build fail despite swarm working

When I try to build my lighting Unreal Editor instantly reports that the lighting build failed, but the swarm agent continues to calculate the lighting and report a job success - it’s as if the editor isn’t waiting for swarm to finish.

Any thoughts on how I can fix this? Thanks.

OK - I have this solved. It’s a permissions issue - I have to run the Swarm Coordinator, the Swarm Agent and the Unreal Editor all with admin permissions. Which means the editor needs to be run directly and not launched from the EGL.