Firefox 43-47 has a preference you can switch if you need to continue using an unverified (unsigned) extension. This removes the protection provided by the verification feature, but that's the same situation as earlier versions of Firefox. And you benefit from the security fixes in newer versions of Firefox. Steps at the end. See: Update Firefox to the latest release.

Regarding a new version of Zone Alarm, I haven't seen any other posts about this software. That could mean it's not a problem, or it might mean their software isn't popular with Firefox users. Either way, you might get a faster response from its publisher. http://www.zonealarm.com/support/

Firefox 43+ requires that extensions be digitally signed by Mozilla. This article has more information: Add-on signing in Firefox.

If no updates are available for an extension you can't live (browse) without, you could make a temporary global exception to the signing requirement. Unfortunately, there's currently no way to only make an exception for specific extensions and therefore you need to be vigilant about bad add-ons creeping in if you do this.

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful.

(2) In the search box above the list, type or paste xpin and pause while the list is filtered

(3) Double-click the xpinstall.signatures.required preference to switch it from true to false -- note that this is for Firefox 43-47 only

naninka said

as the fire fox update at the beginning of this year kept turning off my zone alarm extreme security package, which it said was not verifiable i went back to an older version of firefox which worked with my security package

It is not Firefox that is made to work with Zonealarm or any other antivirus clients.

Your Zonealarm application itself was not affected but rather the version of the extension you had was not compatible with the Firefox version you had at time.

Unlike most extensions, those extensions that tie in with the antivirus client have to made for each new major version of Firefox on Windows.