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Light Building Stuck at 0%


Basically, I'm having trouble getting my lighting to build at all. It starts at 0% and never moves from there. I have tried building in an empty scene as well as the default setup.

I've searched for similar questions and have yet to get any working answers. I've checked that port 8008 and 8009 are not blocked, and made sure that my firewall/antivirus wasn't getting in the way of Unreal and Swarm communicating.

The swarm log gives me this error:

15:15:28: LogSwarmInterface:Error: [TryOpenConnection] Waiting for the agent to start up ... 15:15:28: [TryOpenConnection] Waiting for the agent to start up ... 15:15:28: LogSwarmInterface:Error: System.Net.Sockets.SocketException (0x80004005): An attempt was made to access a socket in a way forbidden by its access permissions

Has any encountered this problem and found a solution? I have tried this with UE4.13, 4.12 and 4.8 but to no avail.

Thanks, Ben

Product Version: UE 4.13
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asked Sep 06 '16 at 01:22 PM in Using UE4

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Hi Ben,

This information on our Wiki for Swarm Agent should help you identify what programs/processes are using the ports for 8008 and 8009: https://wiki.unrealengine.com/Swarm_Agent_Troubleshooting#Swarm_Log:_System.Net.Socket_Error.2FSwarm_Agent.2FCoordinator_Port_Used_By_Another_Process

Unfortunately, I'm not super familiar with reassigning ports or helping with that side of things with Windows, so this may require some googling on your part to find a solution.

In the past when some have given up on trying to track down or change the port assignments they've just reinstalled Windows without dealing with the problem which immediately solved it since the ports were no longer in use by the other processes.

Anyway, I hope this helps at least identify what is being used by those ports.


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answered Sep 09 '16 at 07:01 PM

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Tim Hobson ♦♦ STAFF
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avatar image Ben_M Sep 11 '16 at 10:50 PM

In the end, there was another program blocking the port. Thanks a lot for the info!

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