As of Firefox 57, legacy add-ons (add-ons created using now deprecated technologies, like XUL or Firefox SDK) were disabled, as they are no longer supported – from now on, only WebExtensions are supported.

Meskó Balázs said

As of Firefox 57, legacy add-ons (add-ons created using now deprecated technologies, like XUL or Firefox SDK) were disabled, as they are no longer supported – from now on, only WebExtensions are supported.

Can you elaborate on this? What are "Web Extensions"?

As mentioned in my previous post on this topic, one chronic offender is Flash. And yes, I know that Flash is "outdated", has "security issues" and is "soooooo last century".

I also know that Flash isn't gong away any time soon, like it or or not.

My original question - and this one - has to do with the automagic kill switch for things like Flash. As I said before, the fact that it gets killed isn't the problem. The problem is that it gets killed without warning - often at the most inopportune times.

It also appears that - once this happens - there is little I can do about it without digging into my Firefox files and settings and mucking around with permissions - something I really hesitate to do.

I have no control over the technologies that the web-sites I visit use. I can no more tell sites like the local MLS, HUD, city and state government sites, banks and various businesses that I am compelled to work with how to run their sites, than you can tell Microsoft how to manufacture and market their products.

In an ideal world, everyone would have come completely up to HTML-5 (or whatever the latest standard is), long ago, and we wouldn't have these issues.

This world - and the Web - is far from ideal, and I am compelled to work with things the way they are, not the way I would like them to be.

Thanks for the help!

Jim (JR)

Hi Jim, the Shockwave Flash plugin is governed by different rules than extensions.

(1) By default, Flash is set to "click to play." See: Why do I have to click to activate plugins?

(2) Older versions of the Flash plugin are added to a block list that Firefox downloads from time to time. However, if you have Adobe's updater installed on your system, and you allow the updates when suggested, this should not affect you.

When you have a presentation coming up, you can always use this test page to check that your Flash is up-to-date: https://helpx.adobe.com/flash-player.html. You probably want to add that to your pre-flight checklist.

jscher2000

Thank you! This is the most lucid and helpful answer I have received so far.

Though I have been around (ahem!) "for a while", I haven't learned all the tricks, and your suggestion is golden.

It will absolutely be a part of my "pre-flight" checklist, both "at the gate" (dress rehearsal) and "on the threshold waiting for clearance" (just prior to the presentation).

Jim (JR)