hi kgkphd, mozilla can and will not meddle in third-party code that gets distributed independently - it's the addon developer's responsibility to take care of the compatibility of an extension. as a paying customer of kaspersky you are also paying them for this service! since mozilla is making its release schedule known months/years in advance, a new firefox release can't come as a surprise for a big developer like kaspersky. so please get in contact with their customer support to inquire how they'll make an update of their addon available.

So I stop using Firefox. If it makes life harder for me, I don't need it.

For anyone reading this thread, Kaspersky is in the process of getting its extensions signed/verified by the Mozilla Add-ons team so they will work in Firefox 43 and later. Look for the forthcoming "Patch D".

Meanwhile, the only way to enable them is to make a temporary exception to the signing requirement until they get updated. This is global for all extensions, there's currently no way to only make an exception for Kaspersky extensions.

(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 only

I am not a computer technician. None of this makes any sense to me. However, I would like to have some security on my computer. What is wrong with Kaspersky? Are there any alternatives to Firefox/ I cannot deal with all these problems. I am not a computer technician.

Hi ldq1997, most people here are not computer technicians, so you are not alone. If you take the 1,2,3 step-by-step approach in the above reply (https://support.mozilla.org/questions/1099269#answer-821340) you should be able to get your Kaspersky extensions working again.

I would like to have some security on my computer. What is wrong with Kaspersky?

One important thing to keep in mind is that Kaspersky includes many components to protect your system. Browser add-ons are a little extra included in the package, but they are one of many layers of defense.

I'm not sure you would have better luck finding replacement add-ons that offer such a complete solution. However, if you want to search for alternatives, it would be useful to know which Kaspersky add-on features you use. For example, there is an optional password manager. Do you have Kaspersky store your logins?