Yeah, my researches late (relatively!) last evening said that MacOS versions prior to 10.12 would have the problem. Are you constrained to stay on 10.11.6?
Hmmm. We have an older (waaayy older) iMac in the family room. I'll have to check to see what OS version is running on it - I rarely use it any more (I used to use it occasionally, because that's where our scanner lives, and my wife uses it frequently for that purpose - but I've taken to just unplugging the scanner and plugging it in to my laptop when I need a scan).
So...If you have older hardware, running older system versions, you may have a problem. I found a site that provides a summary list:
- Windows: versions older than Windows XP SP3
- macOS: versions older than MacOS 10.12.1
- Ubuntu Linux: versions older than 16.04
- Debian Linux: versions older than 8
- iOS: versions older than iOS 10 (iPhone 5 is the lowest model that can get to iOS 10)
- Android: versions older than 7.1.1 (but 2.3.6 or newer will work if served ISRG Root X1 cross-sign - whatever that means!)
Thanks to Sabin for finding a patch for those of you with older systems! If you're running one of these older OS versions, and you can upgrade, you probably should (you'll have things crop up other than just philliesphans access); but if your hardware (or some essential legacy software) won't permit that, then patching in a cert may be your best option.