If you switch to the ESR 52 version you'll get another 6 months out of MAFF / MHTML. Hopefully by then a WE (WebExtension) will become available. https://www.mozilla.org/en-US/firefox/organizations/ I am using ESR myself when I "work" this forum, albeit a real old ESR 38 version that can still use some extensions that never got updated beyond Firefox 44.

I'm in the same dilemma as you are; 12 years worth of MAF / UnMHT files saved that were accumulated on 4 different computers.

Another solution might be keeping an older version of Firefox installed, with the related Profile, to use to view the saved MHTML / MAFF files. Just don't use it on the internet, only for viewing "local files" which Firefox 55 has screwed up being able to do. As far as saving new files in that format - I have no ideas on how to do that. But hey, that's the risk of using a file format which has never been recognized as being "universal"; the reason that Mozilla never built that format into Firefox and we have needed to install an extension to "do" that format for so many years.

Hello

Thanks! This is simple. I'll give it a try. Hopefully ....FireFox will see the "error of their ways". This add-on should be at the TOP of their "revamped" add-on list on or before November 14, 2017. I'm not into scripts and webpages.....hopefully someone connected with FireFox is. This is worth supporting $$$.

Regards

JB.

If Mozilla thought that feature was important for Firefox users, Mozilla would have built it into Firefox many years ago. So it's not really Mozilla fault that it doesn't work or doesn't work properly now.

MHTML was a Microsoft specific format that MS was hoping other software developers might adopt as a "standard". AFAIK only Lotus Development Corp and the Opera browser were the only major software concerns outside of Microsoft that ever embraced that format. https://tools.ietf.org/html/rfc2557 And Mozilla is so "standards compliant" (or oriented as such) that MHTML was never seriously considered for inclusion in Firefox.

Overall, fixing or updating the UnMHT and / or the MAFF extension is up to the developers of each extension.

Fine. I don't care WHO does it. But FireFox is like a perpetual BETA project....it throws things against the wall and hopes it sticks. "Saved Files" is no JOKE. Having to start ALL over again.....because Mozilla decides to make changes that impact users systems in a very negative inconvenient manner...is as bad as Microsoft putting out garbage software to quickly for years and then use endless patches to fix it. Chrome is nothing more than a Google puppet.

When you have to deal with malware, ransomware, ID Theft, Hacked credit cards, lousy (paid) customer service for lousy (paid) software, Fake Websites, Online scams, Infected emails, Overpriced ISP's, FCC political lapdogs, Security Clueless retail, government, personal information sites (Equifax) and Russia's favorite punching bags (Yahoo, FaceBook, Twitter ect.) etc. I have no tolerance for a browser "designed" computer "pain in the ass" change(s) that adds ANOTHER mine to the endless Internet minefield. FireFox's trademark IS their addons.

.maff files can be opened with any application that support .zip formats, like Winrar and 7-zip because it is basically a zip container with a different file extension. After you open them with one of those application you can extract the content (a .html file) and open it with any internet browser.

so don't worry about opening those files in future, however, the big issue is with archiving pages in future, since the built option in Firefox is not adequate.

I don't have a problem opening .maff files, but I need to save new ones also, and I'm trying to figure out how.

nevermind.