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Firefox 62 giving me an "Your connection is not secure" error message on all URL's with Mac OS 10.14 and Malwarebytes for Mac

microbarny
microbarny
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Don't know which settings I need to change but when I updated my operating system to OS 10.14 all Firefox web searches bring back the "Your connection is not secure" error message. I looked further on the Advanced Tab on a couple of URL's and got a similar message:

nam01.safelinks.protection.outlook.com uses an invalid security certificate. The certificate is not trusted because the issuer certificate is unknown. The server might not be sending the appropriate intermediate certificates. An additional root certificate may need to be imported. Error code: SEC_ERROR_UNKNOWN_ISSUER

www.aol.com uses an invalid security certificate. The certificate is not trusted because the issuer certificate is unknown. The server might not be sending the appropriate intermediate certificates. An additional root certificate may need to be imported. Error code: SEC_ERROR_UNKNOWN_ISSUER

I use Malwarebytes for Mac (v3.4.29), but that hasn't created a problem with Firefox in the past. Any help would be most appreciated. Thanks in advance.

Don't know which settings I need to change but when I updated my operating system to OS 10.14 all Firefox web searches bring back the "Your connection is not secure" error message. I looked further on the Advanced Tab on a couple of URL's and got a similar message: nam01.safelinks.protection.outlook.com uses an invalid security certificate. The certificate is not trusted because the issuer certificate is unknown. The server might not be sending the appropriate intermediate certificates. An additional root certificate may need to be imported. Error code: SEC_ERROR_UNKNOWN_ISSUER www.aol.com uses an invalid security certificate. The certificate is not trusted because the issuer certificate is unknown. The server might not be sending the appropriate intermediate certificates. An additional root certificate may need to be imported. Error code: SEC_ERROR_UNKNOWN_ISSUER I use Malwarebytes for Mac (v3.4.29), but that hasn't created a problem with Firefox in the past. Any help would be most appreciated. Thanks in advance.

All Replies (1)

jscher2000 - Support Volunteer
jscher2000 - Support Volunteer
  • Top 25 Contributor
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Hi microbarny, this usually is caused by a "man in the middle" intercepting your browsing and generating fake website certificates. I'm not aware that Malwarebytes does that, but Avast, AVG, Bitdefender, ESET and Kaspersky do...

Here are our general support articles:

To try to figure out what software is generating the fake certificates, could you click the SEC_ERROR_UNKNOWN_ISSUER code (it's usually styled like a link) to expand a panel that (hopefully) shows a coded version of the certificate? You can copy/paste that into a reply here and a volunteer can run it through a decoder to see who is listed as the Issuer. Or you can try it yourself on a site like the following (or others that are similar): https://certlogik.com/decoder/