Thank you for your Question. To downgrade to an old version of Firefox, back up your Firefox profile first, as a precaution, and then follow these steps: Download the version you want from http://download.cdn.mozilla.net/pub/firefox/releases/ or http://ftp.mozilla.org/pub/mozilla.org/firefox/releases/ Note: If you are looking for an older version of a Firefox "final" release, look for a download with no letter suffix (e.g., 18.0.2 is the last final release version previous to 19.0). Release versions that end in esr (e.g., Firefox 17. 0.3esr) are Extended Support Release versions intended for organizations. Versions that end in b (e.g., 19.0b6) are Beta releases, intended for users who are testing pre-release versions. Exit Firefox and then uninstall it. Make sure to remove the Firefox installation directory. Install the older Firefox version. You can install Firefox in the same location to minimize any side effects. For example, the Windows registry or other installed programs may expect Firefox to be in the default location (e.g., C:\Program Files\Mozilla Firefox or C:\Program Files (x86)\Mozilla Firefox on 64-bit Windows). After installing the older version, turn off the automatic Firefox Software Update feature (if enabled). Reconfigure your firewall if you have one. If Firefox disables any of your add-ons you probably need to replace it with a version that supports a older version of Firefox. If you experience other problems, create a new Firefox profile and transfer your data to the new profile.

To get off the Beta channel, you need to download and install a Release version of Firefox. To keep Firefox from automatically updating you should disable the Mozilla Maintenance Service, in addition to selecting "Never check for updates". This "service" was created for a purpose other than forcing updates, but it has been used for forcing an update at least once that I am aware of - but probably more often than that. https://support.mozilla.org/en-US/kb/what-mozilla-maintenance-service

As far as Security Suites like Kaspersky not keeping up with the Firefox Rapid Release program, I find it farcical that so-called security application supplies their users with somewhat useless browser add-ons that they don't take the time to keep up-to-date in a timely manner. Most of those silly add-ons just duplicate features that are already built into Firefox, but sourcing their "safe browsing data" from their own source. As far as I am concerned, if they can't keep "their crap" up-to-date they shouldn't include it as a feature of their program, especially for paying customers! An occasional lapse is one thing, but Kaspersky for one makes that a regular habit from what I have seen posted in this forum. Version after version goes by with Kaspersky not fixing one or more of their add-ons - and now it sounds like they might be 3 full Firefox versions in arrears. Time to "fish or cut bait", IMO.

Thanks Turjoe and Edmeister. I'll give those solutions a try. Somehow in the past I managed to get on the beta release channel. Not sure when that happened. I've used the mozilla browsers since one of the very early Netscape versions. I have just become to "feel" more warm and fuzzy safe letting Kaspersky cover my backside.

Warm and fuzzy or not, if a security program automatically install browser add-ons, I expect those add-ons be kept up to date.

Personally, I use Avira! Free just because it is one of few remaining anti-virus application that does not insist upon installing those silly add-ons, many of which duplicate features that are already built into Firefox. To wit; Safe Browsing and Malware / Phishing Protection https://support.mozilla.org/en-US/kb/how-does-phishing-and-malware-protection-work

re kaspersky comment

what is your opinion on avg compatibility with firefox features?

As for AVG, it has been many years since I've used it but it seemed to work okay at the time. Getting off the beta version helped solve the issue. Not sure how that even happened. What I have found over the years is that using only the browser to defend, I get a lot more banners and things seem to take over the search engine so I stick with Kaspersky.

Thanks for all the help

I haven't use AVG-free for many years now, but from what I have seen posted here it does install some Firefox add-ons, and did cause some issues when the Rapid Release program started a few years ago, but so much recently. Kaspersky has been causing a lot of grief recently [since like Firefox 30] and around the Firefox 8.0 or 10.0 versions, with their add-ons not being kept up-to-date.

I use Avira Free - because it doesn't install an add-ons for Firefox.

Avira tried installing one a few years ago in the Free version, but the outcry in their support forum was so huge that within a month they got rid of it. I never even saw that add-on to see what features it added (or duplicated what was built into Firefox) because I was in a non-admin account when the Avira Free program update was installed - just ignored the prompt to re-boot my PC and never switched into the Admin account to allow that add-on to be installed. Been running this PC 24/7 on a UPS since it was built in 2008 and only turn it off to do internal cleaning like once a year; and to replace the UPS twice since 2008, when the battery gave out. Cheaper to get a UPS on clearance than to get a new battery when I would need it.