So now, for all practical purposes it's chrome based and Sarafi, I guess. Which, the latter is a Job's rip off of open source webket, IIRC. Just like the Apple OS is a rip off of Berkeley Unix, can't recall what it was called.

I do remember web designers having to accommodate all the players.

The final effect of that, though, was that web designers quickly found accommodating all the different engine designs to be too costly or bothersome for them... so they increasingly began coding and testing their sites for just a 'select' few engine designs, with all others being deemed "unsupported" by their sites. This dumped the site compatibility effort totally onto the unsupported browser developers, forcing them alone to find workarounds, patches, or engine code changes to address a constant parade of user complaints that their browser wouldn't work on sites x, y, or z. And often, those fixes were only partly successful or caused instability in other areas of the browser. As the Internet evolved, so did the site code... so overlaid on the above was a continual progression of technical and protocol improvements that impacted site code and made it even more difficult for the minor browser players to keep up with sites that only assured their compatibility with a few engine types.

Naturally, in a self-fulfilling cycle, the browser brands garnering highest user market-share quickly became the only brands appearing on many website "supported" lists and so gained even more user share... but Opera never was one of those, lacking the resources to project itself into the public eye as much as could deeper-pocket outfits like Google, Microsoft, or even Mozilla. The result was Opera ASA's eventual decision to replace its Presto engine with the widely-compatible chromium engine. And here we are today...

Didn't Opera also have a Gecko engine?

Nope, not that I can remember.

As noted upstream, I've been with Opera since it was ad supported and I paid whatever the fee was to remove the ads.

I do remember web designers having to accommodate all the players.

@blackbird71 Doesn't MS Edge also use Chrome? Did Google make it open source, or do they pay licensing fees? What is so attractive about Chrome? Opera had their own engines for years that were noticeably better the Windows Explorer, for instance.

Edge now uses a chromium engine, as does Opera - but prior to 2020, Edge instead used proprietary Microsoft engines. Google Chrome also uses a chromium engine, but it adds proprietary functionality to it.

"Chromium" refers to both a specific web browser and the open-source code first developed by Google for Chrome in 2008 but which has since been maintained and increasingly altered by the Chromium Project with inputs from Google and others. 'Chromium' is a web browser simply compiled from current chromium source code; 'Chrome' is a web browser with Google's proprietary alterations of chromium code; 'Edge', 'Opera', 'Vivaldi', 'Brave', etc are chromium-based browsers that each apply their own added code on top of the chromium codebase to insert their own features. In most cases, where the chromium code has limits or architectural constaints, those will also be seen in the various browsers - hence one can indeed refer to them all as a single class: chromium-based.

The history of web browsers and the great "browser wars" is fascinating (to some) and far too long to fully go into here. The bottom line is that once upon a time, there were differing ideas on how a browser should best render a website's coded information on a computer screen... hence differing browser designs appeared over time, not always compatible with one another. Websites began to have to include different code modules for different browsers or risk not showing up properly on various screens. But code costs money to write, test, and maintain; so websites began to limit the browser brands with which they were fully compatible. Eventually, attrition (or Google's bottomless resources) led to most code engines falling into disfavor and browsers had to either adopt a more common approach (which turned out to be chromium) or continue spending great resources maintaining their own proprietary engines. Opera originally had its own proprietary Presto engine, but felt the economic need to no longer maintain it and changed over to the chromium engine instead. Because chromium is open-source, it's essentially free and the various browser makers all have input into the Chromium Project going forward. Looking back, various engines all have their pros and cons, and that debate will probably never be resolved.

@blackbird71 I've never really understood how certificates work. But I don't have issues with Chrome or Firefox, same computer, same OS.

Ok, if Chrome has no cert problems, then an obsolete Win7 cert store is not the cause... all chromium browsers work the same way on this, and both Chrome and Opera are chromium-based browsers.

There isn't anything like Help me understand, See more, etc?

@paulverizzo Most probably your certificates are outdated. What the "your connection is not private" page says the problem is?

It doesn't say.

Firefox uses a cert store brought down from Mozilla's servers instead of Windows' certs, so it won't experience that particular problem.

In any case, With an old and obsolete OS like Win7, you really need to make the effort to update the Windows cert store and assure that the Win7 cert updater will automatically connect to the proper Microsoft site in the future. Win7 may no longer reliably update its cert store after reinstallation of the OS unless you take the effort to make sure the updater is pointed in the right direction.

Update: When I get the "Your connection is not private" page, I found out if I click on "Learn more," there is then an option to proceed. Annoy, but a workaround.

then you need to call the internet provider.

Fortunately, I have a well functioning Opera on my laptop. I tried Sync and nothing synced. Fortunately I was able to copy and paste the Opera Stable folder. Voila!

Then a few hours of use, "Your connection is not private!" Eff! Eff! Eff!

Firefox doesn't not offer to import from Opera, so I selected "Import from Chrome." Says it did, but it didn't. So, once again I am having to build Firefox back up from scratch.

My long marriage with Opera, on my PC is now ended. I'm sad. I'm pissed.

If so and things still don't work, see https://forums.opera.com/post/289817 for how to update your certificates.