Starting up swarm connection freeze

Hello,
I have a problem with rendering lights. Indeed when I run it, it freeze and I have this error in swarm agent:

18:29:21: [ERROR] Channel registration failed. Reason: Une tentative d’accès à un socket de manière interdite par ses autorisations d’accès a été tentée
, Callstack: à System.Net.Sockets.Socket.Listen(Int32 backlog)
à System.Net.Sockets.TcpListener.Start(Int32 backlog)
à System.Runtime.Remoting.Channels.ExclusiveTcpListener.Start(Boolean exclusiveAddressUse)
à System.Runtime.Remoting.Channels.Tcp.TcpServerChannel.StartListening(Object data)
à System.Runtime.Remoting.Channels.Tcp.TcpServerChannel.SetupChannel()
à Agent.AgentApplication.Main(String[] args) dans D:\Build++UE4\Sync\Saved\CsTools\Engine\Source\Programs\UnrealSwarm\Agent\AgentApplication.cs:ligne 133.

It looks like an attempt to access a socket in a way forbidden by its access permissions was attempted. So maybe an abandoned instance of swarm is still holding on to its socket. If you reboot your computer does this error go away?

Thank you but i have reboot my computer and it does not work