Over the past month I've had 1 or two failures to retrieve a page about once per day.

Not knowing what might be the cause, I tend to wait 5 minutes and then return to that Tab again.
This is almost always successful.

I usually have about 12 Forum tabs open continuously, if that helps.

@transparent, my experience is very similar, but didn't realise it was that frequent. I have the hosts trying to diagnose the issue, and may involve shifting to a more powerful server.

John Isner is a powerful server @editor 

The other indication I have that there's something sluggish about the forum server, is that the screen refresh is getting slower.
It's now almost always the case that I will first see a portion of a graphic from the top of the page, but at an enormous size.

There's enough time for me to actually get a screenshot:

I've left that graphic full size, so you can see the progress notification at lower-left.

After the massive graphic disappears, I then see text from the requested page, but with no frames or formatting yet applied:

In most cases, the full page layout then arrives.
But there have been occasions when it doesn't, and I have to manually refresh the tab.

No, these page rendering lags aren't happening for other sites... just this Forum.

It matters not how may active tabs I have,
nor what else is running apart from the browser (Firefox),
nor how free memory there is.

@transparent ditto, exact same behaviour , on almost all page loads from this forum today and yesterday. at first I thought I might be having an ISP issue that I needed to debug, but its only this forum.

@transparent same here.

So after countless emails and diagnostics with the hosts, between the traffic and size of database file for the forums in particular, we’ve decide to upgrade and ramp up to a faster, more powerful, more expensive server. At some stage in the next 48-72 we’ll get transitioned to the new server. There will be a downtime while data gets migrated, with a further delay for the domain to get pointed to the new server. So if the site is inaccessible for a long time, that’s probably what’s happening.

As an update, I have been informed that we're in the support "queue" for data migration which also includes our other website myhomefarm.co.uk – they expect for that start around 12pm today. How accurate that is as a time, I don't know, but I suspect that at some stage this afternoon the site will become completely inaccessible for a duration of time. They have informed me the downtime will be around an hour, which I'm taking with a pinch of salt because whenever I've done data and domain migrations it takes a lo longer than that. But we'll see.

Thanks for your patience everyone, and I hope that it'll be worth the effort. 

Two minutes to go.
I wish you well as we travel through the portal.
May we meet again on the other side! 😱 

@transparent, the migration hasn't started yet... they must be running behind schedule.

The timing isn't of any great concern, Mars.
Living deep in the West Country, I'm used to things arriving later than elsewhere...

... usually by a few decades. 😎 

Still no news... looking less and less likely that it'll be happen today... 

Well that's a coincidence...

I was just speaking with one of the Four Horsemen of the Apocalypse, and those were his very words!