IDE 'Find in Reference' suddenly not working

If I select a line of code in a sketch, for example with the text cursor inside the string 'DigitalWrite' and use 'Help > Find Reference (or the Ctrl+F shortcut), my browser Waterfox normally takes me to that page in the Reference section of Arduino's site. But suddenly it's now failing. It puts this in the URL box
file:///C:/Program%20Files%20(x86)/Arduino/reference/www.arduino.cc/en/Reference/DigitalWrite.html
and spins indefinitely.

I appreciate that this is not a programming issue, and probably not an Arduino issue either. But anyone have any idea what may be happening to cause this recent change and how to fix it please?

Are you certain that it used to take you to a page on the Arduino site ? All of the versions of the IDE that I have used over the years, currently1.8.13, have taken me to a local file on my PC, which is what is happening to you

Thanks for your fast reply, after which I’m ready to conclude I was mistaken and it did not take me to the web site. But it defintely does not work right now. Is it OK for you? I ask because some googling turned up posts about site problems today.

Ah! I tried it before beginning this post, waited a couple of minute as it spinned and then started composing this. But now I see it has successfully delivered that local page. I’m guessing 3-5 minutes or so!

It is working for me but very slowly (about20 seconds to open the page), but as I have not used it for a long time I cannot say when it last worked quickly

As at Monday 9 November 2020, about 1415 UK GMT, it's taking about 60 secs to display. But the tab (in Waterfox or Firefox) continued to display is spinning wheel. So I'm unaware it's available while working in another tab.

All that's academic, of course, as a full minute to get to a page for immediate context help is unacceptable. Any idea of the cause? Meanwhile I'll keep the Reference page open: Arduino Reference - Arduino Reference

IDE 1.8.5, the relevant data loads (so the page is usable) in a few seconds but page takes ages to finish loading.

Possibly still a side effect of trying to mitigate the DDoS attack.

sterretje:
IDE 1.8.5, the relevant data loads (so the page is usable) in a few seconds but page takes ages to finish loading.

Possibly still a side effect of trying to mitigate the DDoS attack.

Thanks. On googling around I see that reported here:

How did you learn of it please?

Possibly when arduino became aware of it, I saw a glimpse of (possibly) a warning about a DDoS when I entered this website; it was there and disappeared in a second or so. That's maybe a week ago or so, can't remember.

And next reading through new threads in website and forum section, there were mentions in a number of replies.