tailscale: Windows: suddenly logged out, "tailscale is stopped", "tailscale up" and login doesn't fix it

Is this a dupe of #3170 ?

Not really. That was already fixed (coming out soon), but that’s just cosmetic in this bug. It’s making your logs ugly, but it’s not the problem.

That wsl.exe error/spew is fixed in the latest builds (not yet released to the stable branch).

Oh no indeed. I got back from a walk, tailscale icon is missing in systray, connectivity is down.

Windows Services thinks its running.

When Tailscale on Windows is not running in “Run Unattended” mode, the service shuts down when the GUI disconnects.

So if your systray icon is gone, which I see it is, then the Tailscale service shuts down by design (but stays running, idle):

2021-12-14T15:58:53.582-08:00: Switching ipn state Starting -> Running (WantRunning=true, nm=true)
2021-12-14T15:58:53.583-08:00: ipnserver: conn8: ReadMsg: read tcp 127.0.0.1:41112->127.0.0.1:62516: wsarecv: An existing connection was forcibly closed by the remote host.
2021-12-14T15:58:53.583-08:00: client disconnected; stopping server
2021-12-14T15:58:53.583-08:00: LocalBackend.ResetForClientDisconnect

So the question is why the system tray GUI app shut down.