PVR process stops working

[MrBrunes]

Occasionally I notice that the PVR process has stopped downloading.
Now that it's configured to auto-file programmes into folders it's
slightly harder to spot that a single download folder isn't being
updated, but often a clue is the disappearance of the CMD window.

Then I try to use 'Run PVR Scheduler' again but it fails with:
""ERROR: Quitting - PVR is already running (process ID: 13960)"

Searching for 'iplayer' in Event Viewer's application log doesn't find
anything recent.

The PID never shows up in Task Manager or Process Explorer so it's reboot time.

How can I diagnose this?
Failing that, is there any way to make the PVR process more resilient,
or failing that is there an easier method to detect that it's stopped
downloading?

The docs mention the possibility of using the Windows scheduler for
the PVR at https://github.com/get-iplayer/get_iplayer/wiki/documentation/09a72bf76c131c8932bbf0aef1eeb95ec85049b9#scheduling-the-pvr
but the external link is invalid.