Well the good news is I figured out why my server can’t download updates through the update manager – it turns out the server can’t see the internet.
This is exceptionally weird because the internet can see it. I’ve set up port forwarding on my Virgin Superhub router so I can SSH into the server, but can’t reach the internet on the way out!!
Also can ping the router etc. just fine.
Turned out I’d screwed something up in my router last night – I had set up a MAC filter for the server, and since the default was Allow All, anything in the filter list was blocked. OOps.
All good now, but my “Update Manager” still doesn’t seem to work at all. Problem for another day though.