I can't build anything

Hello
I have a problem, I can’t build anything. My firewall is over (avast), it accept unreal engine and swarm agent.
My computer : 16 go ram; GeForce GTX 1060 with 6go; windows 10; 250ssd.
swarm agent say : 21:42:02: [ERROR] Channel already registered, suggesting another SwarmAgent or client is running.
21:42:02: [ERROR] If you feel this is in error, check your running process list for additional copies of
21:42:02: [ERROR] SwarmAgent or UnrealLightmass (or other client) and consider killing them.
21:42:02: [ERROR] Sleeping for a few seconds and trying again…

My CPU name begin by a letter and I delete C:\Users[UserName]\AppData\Local\UnrealEngine[VersionNumber]\Saved\Swarm\SwamCache
but i don’t know if my computer uses non latin character …
Thank you a lot