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‘No Mac was free to start this session’

You might be here because: “No Mac was free to start this session” · “No phone was free to start this session” (older app versions) · “session closed right away” · “it launched then instantly ended” · “dispatch_no_live_node” · “is the service down” · “nothing happens when I launch, then it says ended”

Short answer

None of the Macs that run sessions could take a new one at that moment, so your session was closed before it started. Nothing about your profile or proxy caused it. Wait a minute or two and launch again; that usually works.

Check first

  • Wait 1–2 minutes, then launch the same profile again.
  • Signed in and online? An offline app shows other messages, not this one.
  • Nothing to fix in the profile or proxy: the Mac is chosen before either is looked at.

Likely causes and fixes

  1. No Mac available. When no live Mac can take a launch, the start is refused before any session exists (503, code: "dispatch_no_live_node"); when the Mac it was sent to had just gone out of service, the server closes the session with reason dispatch_no_live_node. The app shows “No Mac was free to start this session — None of the Macs that run sessions could take a new one just then, so this one was not started. Nothing about your profile or proxy caused it — starting it again in a minute or two usually works.”. Fix: retry shortly.

  2. The launch could not be handed off. A launch that fails to dispatch is closed with reason dispatch_failed. Same fix: retry.

  3. From code. The create answers 503 with code: "dispatch_no_live_node" and a Retry-After header, and nothing is created: send the same request again after the wait — for an agent session the same Idempotency-Key is fine, because nothing was stored under it. A session that closes moments after its create with that reason is the second case above: create it again with a new Idempotency-Key — the same key replays the closed session (which routes honour the header, and how it is scoped, is listed on the Idempotency reference).

  4. It keeps happening. Repeated refusals over several minutes mean capacity is short on our side, not something in your account.

If it still fails

Rule of thumb: if it keeps happening for more than a few minutes, press Talk to a person in this chat (or open Help) and include the time and the session ids shown as ended. This is a service-side condition; a person will confirm status. No account or billing action is needed from you.