Kaspersky is a security program that is available in both a stand-alone program and Mozilla Firefox add-on. The Kaspersky Firefox add-on scans files that are downloaded in Firefox to ensure that they are safe for the computer. The Kaspersky add-on requires a special security certificate to run. Although many Kaspersky users don't experience problems with running the Firefox add-on, you may find that there are certificate errors with Kaspersky in Firefox. There are four primary causes for certificate errors, and by troubleshooting through each cause, you can fix the certificate errors issue.
Although Mozilla Firefox generally handles Kaspersky security certificates well, sometimes it does have problems with them. This typically occurs when using a version of the Firefox browser that is either too new or too old for the Kaspersky plugin. The problem may also occur because the Firefox browser has become corrupt. In both cases, the fix is to reinstall or update Firefox on your computer. Follow Mozilla's instructions for doing so.
Just as with Mozilla Firefox, occasionally Kaspersky may be the cause of the security certificate problems in Firefox. This usually happens when you are using a very old version of the Kaspersky add-on that doesn't work properly with the Firefox browser. Like Firefox, this may also happen because Kaspersky has become damaged, usually due to a virus or piece of malware. You can typically resolve this issue by installing the newest version of the Kaspersky add-on to Firefox.
Even if your copy of Mozilla Firefox and the Kaspersky plug-in are fine, certificate errors may persist due to issues with the certificate itself. When Firefox reads the certificate, it checks to make sure that the certificate is valid. If the certificate is not valid, either due to being incorrectly configured or damaged, Firefox will display an error message. You may be able to fix the issue by re-loading the certificate.
Certificate errors with Kaspersky in Firefox may be caused by problems with Firefox's security settings. If Firefox is not properly configured to work with certificates, it will show an error message any time a certificate is loaded. Consult Firefox's support page for help on configuring the security settings. The certificate errors may also occur because your computer's firewall is blocking Internet access for the certificate. You can fix this by temporarily disabling the firewall or adding an exception for Firefox.