Ever diligent, I managed to find other sites which gave me the same message—all were weather-related (because it’s snowing and I want to know whether to push ahead or hunker down), but not all weather-related sites did this.

I don’t think it’s ever happened on my slightly newer (but still old) iPad—just the PowerBook. Doesn’t happen on my iPhone. I did automate the time/date/time zone settings on the PowerBook per your suggestion above, but no change even after re-starting. So *maybe* it’s an old OS problem, not an iOS issue.

Here's what the experts - our webhost - had to say - edited for clarity/context:

I said:

Users - a very few - continue to have intermittent certificate issues / warnings.

today:
1: "...older Powerbook running OS 10.11.6, using Safari on a hostel wifi network. The address bar says “https://horizons unlimited.com” and the alert reads “[graphic of padlock with a diagonal slash through it] This connection is not private. This website may be impersonating “www.horizonsunlimited.com” to steal your personal or financial information. You should go back to the previous page.” This is followed by a pair of buttons: “show details” and “go back.”"

Grant said: He also had the same issue "recently", so second time. He's on our site pretty much daily, and is a moderator.

their reply:

These platforms would have worked up to September 2021 but will no longer validate Let’s Encrypt certificates.
macOS < 10.12.1
...older Powerbook running OS 10.11.6


2: I (Grant) quoted user:

2: ...Still intermittent problem (including right now as I write this at 20.19 in Germany. On Wi-Fi and 4g. Relatively new Samsung phone. Time supplied by network provider. Like I said before this problem only occurs for me on HU, never on any other website/forum."

I (Grant) had an issue a number of days ago myself, on Win 10, but a refresh and restart fixed it. I'm aware of the thread: https://letsencrypt.org/docs/dst-roo...eptember-2021/


Their reply:

...new android phones/devices should not have an issue. However, older ones will and you may want to clarify with the user how old the device is. For reference from Lets Encrypt's compatibility page:
Known Incompatible
Android < v2.3.6
-------------------------------------------------

I then asked them:

"Thanks, that helps - but is there a workaround for those with older devices? Not everyone is going to upgrade for us..."


NOTE: There isn't ACTUALLY AN ISSUE WITH THE HUBB! It's only a certificate incompatibility. You CAN tell your browser to add an exception and off you go. You should NOT do this permanently for any site you don't trust. Hopefully you trust us, but we don't blame you if you don't to this level. :) For now, it's ok. We will have to see where we go with Let's Encrypt and how this gets solved.
Also NOTE: IF you have this issue with the HUBB, you WILL have it on other Let's Encrypt certificate sites. It's NOT just us. thankfully...

Hopefully that will help clarify the issue. :)

After further discussion with them, it looks like the only solution is a different certificate. And that’s a whole world of pain, aggro and cost I’m not looking forward to. And it won’t be instant.
I’m on it, :censored:

Thanks for looking into this, Grant. I’ve got no particular tech skills, and I’m definitely prone to hanging onto old devices even long after my neighbors have given them up, but I have to wonder about the rest of the world, perhaps not so thoroughly driven by the need to update constantly. I’m not special or unique.

The laptop I’m carrying (OS 10.11.6) is actually by far the *newest* of my laptops, and I’m carrying it only because I’m traveling by car, not bike or public transport. It cost about $2800 CAD only eight or ten years ago. I’m not ready to toss it aside like my neighbors would, and I can’t believe that folks in less prosperous areas of the world would be any more ready than I am.

At home I mainly use a desktop and a tablet, both 6 or 7 years old, and from the sound of it I should expect to start running into problems with these, too, within a couple of years. It seems appropriate to wonder how many others out there in the world have encountered these security alerts and just not bothered to pursue any further.

My phone is newer, but not so new that it wasn’t abandoned by Apple right after I bought it (at an appropriately huge discount). In any case, there is no way I’m using a phone for web access, except when I’ve got no other option—I’ve got enough postural issues without hunching over a tiny screen for hours at a time.

Here’s hoping there’s a cheap, easy, functional solution. Please let me know of any way I can help (in my generally clueless state).

Mark, I hear you - my laptop is 10 years old! And still fine! My phone is 5? years old iPhone 6s+ - so about 7 generations behind, but I have no issues with it on HU.
Thanks for the offer of help, but this is so highly technical I have to get someone else to do it, it's beyond my skills. And hurts my brain...

Mark, Chris, anyone else with the issue, please go to https://new.horizonsunlimited.com and see what happens. Probably best to start a new browsing session to be sure of separation.
"new" also uses Let's Encrypt, but through a different host. Wondering if that will make a difference.
thanks!

It was a noble effort, but no—same thing happens.

Same problem for me too

I tried again last night to ignore the danger message and click through. After a couple of increasingly threatening windows, my computer refused to go further—that is, it’s wouldn’t let me access the site. I didn’t explore past this point, i.e., look for a workaround; I just switched back to my tablet, which still works.

Update: Last 3 days, the security warning no longer appears for me. On both Wi-Fi and mobile internet. No, I didn't bother clearing my browser cache in the last week or so either.

Thanks Chris! Excellent - sounds like the Let's Encrypt certificate is finally working correctly. I've been scouring everything, may have fixed it without knowing! :)
Anyone else ok, or having the issue?

Looks like I was tempting fate by saying all was back to normal... The problem is back. Incredibly odd that it's so intermittent.

and we all know how hard "intermittent" issues are to troubleshoot. Crrrap.
Ok, working on it best as.

Apologies for claiming it was an intermittent issue. Seems permanent as per screenshot when I click on address bar on the browser. The browser just can't be bothered to scream the warning at me any longer...

Remains the same as ever on my laptop.