SEC_ERROR_UNKNOWN_ISSUER
Yesterday I have reinstall the Windows. It's about Windows 7 Ultimate RTM 7600. That I mention a short period of time I did not use antivirus software year, the security suite. But today I have installed Kaspersky Total Security, the latest version. After I installed, I can no longer access many sites like www.google.com youtube.com facebook.com yahoo.com etc. I have scanned (deep scan) with Kaspersky Total Security and no viruses or threats. I also scanned with Malware Bytes and no threats, no malicious objects. Then? I get this error, and Mozilla Firefox 50.0 do not let me access to those sites. I don't understand why. How do I solve the problem? What to do? Thank you SEC_ERROR_UNKNOWN_ISSUER
Chosen solution
Did you follow the Learn more link that should bring you to the How to troubleshoot security error codes on secure websites article? You may need to disable Kaspersky’s scanning of encrypted connections or use an alternative method, as described there.
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Did you follow the Learn more link that should bring you to the How to troubleshoot security error codes on secure websites article? You may need to disable Kaspersky’s scanning of encrypted connections or use an alternative method, as described there.
Well yes I have read and I solved the problem. But is not good to let Kaspersky Total Security so. Scanning encrypted connections upon requests from protection components. It works in this way. Thank you very much for promptness. I'm thinking to don't be affected. Will be a problem if I don't scan ecrypted connections? I mean to don't Jeopardizing the data security of my PC and obviously the internet connection. As we all know there are many online threats, and stealing identity or money, it is very dangerous. The Internet is an unsafe environment. Thank you very much
Modified by gaddy
Glad it helped. I understand you disabled scanning of encrypted connections? If so and you would rather allow it, you can either use the other method mentioned there (try to trigger a reinstall of the Kasperksy certificate), or uninstall Kaspersky entirely and reinstall it. I’m not sure if Kaspersky’s encrypted connection scanning should work, or whether it just has ongoing issues importing its certificate into Firefox’s certificate store. Since I understand you installed Kaspersky after Firefox was already installed (which is in fact the proper way), reinstalling may not help.
As for using internet security products and their features including SSL scanning: Firefox checks encryption using its own certificate store anyway (which is what you saw happening) instead of Kaspersky doing it for you. Being a little picky on what features to use in Internet security products may be good in general. Not all they offer is required, so "double" features (as in "Firefox already does that by itself") can cause trouble, similar to 2 pieces of firewall software.
It may be good to know that with regard to Firefox and certificates, things are going to change in the near future so that security products may likely have (or cause) less issues like these. It would also mean users will less run into issues where Firefox may not work, but other browsers still may.