hi, first please make sure that the date, time & timezone are set correctly on your system. if this doesn't solve the issue (or it is already set properly), a solution depends on the individual circumstances:

• what is the error code shown when you click on advanced on that error page?
• please also give us more information about the error by clicking on the error code, copying the text to the clipboard and then pasting it here into a reply in the forum like shown in the screenshot.

thank you!

Your connection is not secure

The owner of search.yahoo.com has configured their website improperly. To protect your information from being stolen, Firefox has not connected to this website.

This site uses HTTP Strict Transport Security (HSTS) to specify that Firefox may only connect to it securely. As a result, it is not possible to add an exception for this certificate.

Learn more…

Report errors like this to help Mozilla identify and block malicious sites

search.yahoo.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

this is on all search engines

thanks, then please also provide the second part of the information i've asked for (like shown in the screenshot). this will likely tell us, what in particular is tampering with your secure connections...

here it is

no, on that site, please click on "Advanced", then on "SEC_ERROR_UNKNOWN_ISSUER", then on "Copy text to clipboard" and then paste the result in text form here into a reply field.

https://search.yahoo.com/search?p=wgoh&fr=yfp-t&fp=1&toggle=1&cop=mss&ei=UTF-8

Peer’s Certificate issuer is not recognized.

HTTP Strict Transport Security: true HTTP Public Key Pinning: false

Certificate chain:

MIIHXTCCBkWgAwIBAgIRANv1XDceE05yzf5UXcKVWt8wDQYJKoZIhvcNAQELBQAw KzELMAkGA1UEBhMCRU4xHDAaBgNVBAMME0FkZ3VhcmQgUGVyc29uYWwgQ0EwHhcN MTgwNDMwMDAwMDAwWhcNMTgxMDMwMTIwMDAwWjByMQswCQYDVQQGEwJVUzETMBEG A1UECBMKQ2FsaWZvcm5pYTESMBAGA1UEBxMJU3Vubnl2YWxlMR0wGwYDVQQKExRZ YWhvbyBIb2xkaW5ncywgSW5jLjEbMBkGA1UEAwwSKi5zZWFyY2gueWFob28uY29t MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDRWkcUT9jk2PFh5Mwb0yjQgIJU 0CT55/zvR9YiqmEQv+wccKgfYNj2okLywJIyevuHe9ngmYm/fsOQ3dg5F+1LrJSf 6LOOAIs7qO3aCiml9wXdd1CgGVRqwdsVv4tABCRMk7qvh9b0WUkdlNr3HQHdrI6K /fz+bWdoRMK1HsrHDQIDAQABo4IEtzCCBLMwggSCBgNVHREEggR5MIIEdYISKi5z ZWFyY2gueWFob28uY29tghBzZWFyY2gueWFob28uY29tghBzZWFyY2gueWFob28u bmV0ghIqLnNlYXJjaC55YWhvby5uZXSCD2xvY2FsLnlhaG9vLmNvbYIRKi5sb2Nh bC55YWhvby5jb22CDm1hcHMueWFob28uY29tghAqLm1hcHMueWFob28uY29tgg5i b3NzLnlhaG9vLmNvbYIaKi5hbnN3ZXJzLnNlYXJjaC55YWhvby5jb22CGCouYXV0 b3Muc2VhcmNoLnlhaG9vLmNvbYIXKi5ibG9nLnNlYXJjaC55YWhvby5jb22CHCou Y2VsZWJyaXR5LnNlYXJjaC55YWhvby5jb22CHSouZGljdGlvbmFyeS5zZWFyY2gu eWFob28uY29tghoqLmZpbmFuY2Uuc2VhcmNoLnlhaG9vLmNvbYIYKi5mb3J1bS5z ZWFyY2gueWFob28uY29tghgqLmdhbWVzLnNlYXJjaC55YWhvby5jb22CGSouaW1h Z2VzLnNlYXJjaC55YWhvby5jb22CHCoua25vd2xlZGdlLnNlYXJjaC55YWhvby5j b22CHCoubGlmZXN0eWxlLnNlYXJjaC55YWhvby5jb22CGCoubG9jYWwuc2VhcmNo LnlhaG9vLmNvbYIXKi5uZXdzLnNlYXJjaC55YWhvby5jb22CGSoubW92aWVzLnNl YXJjaC55YWhvby5jb22CGioucmVjaXBlcy5zZWFyY2gueWFob28uY29tghgqLnNo aW5lLnNlYXJjaC55YWhvby5jb22CGyouc2hvcHBpbmcuc2VhcmNoLnlhaG9vLmNv bYIZKi5zcG9ydHMuc2VhcmNoLnlhaG9vLmNvbYIVKi50di5zZWFyY2gueWFob28u Y29tghgqLnZpZGVvLnNlYXJjaC55YWhvby5jb22CE3lib3NzLnlhaG9vYXBpcy5j b22CEXlzcC55YWhvb2FwaXMuY29tgg8qLnlzbS55YWhvby5jb22CD3NvbG8tc2Vh cmNoLmNvbYIRKi5zb2xvLXNlYXJjaC5jb22CGXBhcnRuZXJpbnNpZ2h0cy55YWhv by5jb22CHWFwaS1wYXJ0bmVyaW5zaWdodHMueWFob28uY29tgg5zZWFyY2guYW9s LmNvbYIQKi5zZWFyY2guYW9sLmNvbYIQcmVjaGVyY2hlLmFvbC5mcoISKi5yZWNo ZXJjaGUuYW9sLmZygg1zZWFyY2guYW9sLmNhgg8qLnNlYXJjaC5hb2wuY2GCEHNl YXJjaC5hb2wuY28udWuCEiouc2VhcmNoLmFvbC5jby51a4IMc3VjaGUuYW9sLmRl gg4qLnN1Y2hlLmFvbC5kZYITbXNhcHAueWFob29hcGlzLmNvbYIScmVzZWxsZXIu eWFob28uY29tghNkb3dubG9hZHMueWFob28uY29tghd0dy5kaWN0aW9uYXJ5Lnlh aG9vLmNvbYIXaGsuZGljdGlvbmFyeS55YWhvby5jb20wDAYDVR0TAQH/BAIwADAd BgNVHSUEFjAUBggrBgEFBQcDAQYIKwYBBQUHAwIwDQYJKoZIhvcNAQELBQADggEB ALYRp4PHZZbC9nwsI/z0BZk33YDT4tEPCa9SZZ/a6/h1TQS60bNWBRj3V0mjgGPA a7rGPfBnW6PNNK/saGexMsAP64681qXk1wZZRQz/XYxdTU8f6ci2NTnOFaJiygqt 56QeeTIwXeoXSdna0lJ/UeQSzDokDDgstn4/jvHTFdwwjqexjyzsb6ptX7HKBihe XrnFthtRMkiFgm/uNoKkyX7af64IS1l8DO+pRM4QcZCbGgZlGD3L8WQTCnscfbWl 7Hk/HsJojZofJaCPZ00OWRBxHQGsDbpOFMCCYZxCYluXPN9/pXk5CvhDQ7iNAIY/ +qgO/9UVaQuFU0vxVixZSyg=

thanks, so it appears to be the adguard software running on your system that is intercepting all secure network traffic. they have a page where they explain how to solve issues with certificate errors here: https://kb.adguard.com/en/windows/solving-problems/connection-not-trusted

had disable I have 6.2 that was for 6.1 thanks for you help