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are you using Fortigate? They currently have an issue:&nbsp;<a href="https://kb.fortinet.com/kb/documentLink.do?externalID=FD53305" rel="ugc">https://kb.fortinet.com/kb/documentLink.do?externalID=FD53305</a>
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are you using Fortigate? They currently have an issue: https://kb.fortinet.com/kb/documentLink.do?externalID=FD53305 [https://kb.fortinet.com/kb/documentLink.do?externalID=FD53305]

consultant

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No, we are using SonicWALL. But i will check the URL you provided. Thanks!
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No, we are using SonicWALL. But i will check the URL you provided. Thanks!

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What are the date settings on the computer? &nbsp;Is it getting time from NTP server?
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What are the date settings on the computer?  Is it getting time from NTP server?

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It's a domain joined PC.<br>Another PC on the same domain does not have this error. &nbsp;
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It's a domain joined PC.
Another PC on the same domain does not have this error.  

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<p>Hi SSL experts!</p><p>A user reported that he's got a "certificate error" when visiting a web site which had no problem previously. (please see attached screenshot as below)&nbsp;</p><p>However, this web site is totally normal with no certificate error when I open it on my computer.&nbsp;</p><p>He also said he frequently sees this certificate error when visiting other websites as well these days.&nbsp;</p><p>It looks like the problem is on his own computer but what is it?</p><p><br></p><p>Any thoughts?</p><p>Thank you!</p><p><a href="https://filedb.experts-exchange.com/incoming/2021/10_w41/1574472/1633359740907.png" rel="ugc"><img src="https://filedb.experts-exchange.com/incoming/2021/10_w41/1574472/1633359740907.png" class="fr-fic fr-dib"></a><br></p>
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1633359740907.png


Hi SSL experts!
A user reported that he's got a "certificate error" when visiting a web site which had no problem previously. (please see attached screenshot as below) 
However, this web site is totally normal with no certificate error when I open it on my computer. 
He also said he frequently sees this certificate error when visiting other websites as well these days. 
It looks like the problem is on his own computer but what is it?
Any thoughts?
Thank you!

Website &quot;certificate error&quot; only occurs on one computer, why?

HTTPS is a protocol for secure communication over a computer network which is widely used on the Internet. HTTPS consists of communication over Hypertext Transfer Protocol (HTTP) within a connection encrypted by Transport Layer Security (TLS) or its predecessor, Secure Sockets Layer (SSL). The main motivation for HTTPS is authentication of the visited website and to protect the privacy and integrity of the exchanged data. HTTPS is widely used for protecting page authenticity on all types of websites, securing accounts and keeping user communications, identity and web browsing private.

Website &quot;certificate error&quot; only occurs on one computer, why?

Website "certificate error" only occurs on one computer, why?