Hi there, I’m sure I’m missing something really simple here but I can’t seem to build the lighting at all. I click ‘build lighting only’ and then when I click play there is an error message saying lighting needs to be rebuilt.
I have noticed that the Build Status dialogue box appears only for a split second. I’m assuming this is causing the problem as I have enough lighting and assets in my scene to keep the light build busy for more than a split second.
Thank you for reading
Try disabling static lighting in World Settings by hitting “No Pre-Computed Lighting” then rebuild.
Edit: Just so you know this will remove static lighting, but /should/ allow you to build
Also, have you tried building all levels? Do you still get the error?
Hey !
Probably there is some error preventing light from Building. Navigate to Top bar -> Window -> Developer tools -> Message log and see if there is something off. If it is - please post it here so we can help you to solve this issue 
Hey guys thanks for responding. I will try your suggestions when I get home later and will post my results.
@Lindsay Aries: In regards to removing all static lighting when I go into play mode everything will run very slowly. For taking a screenshot of my scene however this will probably work.
Hey zeORB, when I build geometry it only tells me I need to rebuild lighting. When I then click Build Lighting Only this message then disappears but when I click play I still have the error message i the top left saying lighting needs to be built 22 unbuilt objects
Ok so it seems to only be an issue with the latest build (4.7.3). I installed 4.6.1 and the light build worked exactly as it was supposed to
Update: I installed UE4 (build 4.7.3) onto my work computer and it worked just fine. The first time I ran the lighting build it told me a firewall was blocking swarm and if I wanted to allow it through the firewall. After allowing it through it built the lighting and didn’t prompt me again after that.
Previously, I had temporarily disabled my firewall on my home computer to see if it that would fix the problem but it didn’t work. However, I’m pretty sure this is a firewall problem and I probably missed something last time.
I’ll have another look at it tonight and post my results.
Thanks for reading
I have done everything I can regarding the firewall but no success.
This is what I get in the log for Swarm Agent
21:06:49: Starting up SwarmAgent …
21:06:49: … registering SwarmAgent with remoting service
21:06:49: … registering SwarmAgent network channels
21:06:49: … initializing SwarmAgent
21:06:49: … certificate check has failed
21:06:49: … initializing cache
21:06:49: … using cache folder ‘C:/Users//AppData/Local/UnrealEngine/4.7/Saved/Swarm\SwarmCache’
21:06:49: … recreating SwarmAgent cache staging area
21:06:49: … initializing connection to SwarmCoordinator
21:06:49: … using SwarmCoordinator on RENDER-01
21:06:51: … SwarmCoordinator failed to be initialized
21:06:51: … initializing local performance monitoring subsystem
21:06:53: … initialization successful, SwarmAgent now running
21:06:58: [Interface:TryOpenConnection] Local connection established
21:06:58: [Interface:OpenJob] Error: Invalid namespace
Any ideas what these errors are about?
, try to delete SwarmCache in C:\Users\YourUsername\AppData\Local\UnrealEngine\4.1\Saved\Swarm\SwarmCache
If it does not help - create post on Answerhub
This didn’t work. Everytime I deletedthe folder it would reappear when I attempted to build the lighting.
I have now posted on Answerhub
Thanks anyway