Why is Swarm taking forever to export scene?

I know this seems to been posted for a long time, but this is the first I come to have this issue and have not found any info as of yet. I have recently migrated my project from UE 4.17 to UE 4.18 and now I am having issues with building the project. It seems to take for ever (4 days now progress still at 0.00%) just to Export the Scene (Gray bar part). I do seem to have the following in the Log and I hope it may be of help to any one that may help me to solve this issue.

11:35:09 AM: [Interface:TryOpenConnection] Local connection established
11:35:11 AM: [Job] Accepted Job 0A528249-477B1CB3-705C53B0-600798CB
11:37:32 AM: [Interface:EndJobSpecification] Error: Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index System.ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index
Server stack trace:
at System.ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument argument, ExceptionResource resource)
at Agent.AgentJob.EndJobSpecification()
at Agent.Agent.EndJobSpecification_1_0(Int32 ConnectionHandle, Hashtable InParameters, Hashtable& OutParameters)
at System.Runtime.Remoting.Messaging.StackBuilderSink._PrivateProcessMessage(IntPtr md, Object[] args, Object server, Object[]& outArgs)
at System.Runtime.Remoting.Messaging.StackBuilderSink.SyncProcessMessage(IMessage msg)
Exception rethrown at [0]:
at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
at NSwarm.IAgentInterfaceWrapper.EndJobSpecificationDelegate.EndInvoke(Hashtable& OutParameters, IAsyncResult result)
at NSwarm.IAgentInterfaceWrapper.EndJobSpecification(Int32 ConnectionHandle)
at NSwarm.FSwarmInterface.EndJobSpecification()

Thanks for any help or tips.

Did you ever find a solution to this? I’m having the same issue.

Nope, not yet. I have yet to figure why.

Deleting and re-importing the Light Mass Importance Volume fixed this error for me.