I was going to look at a friend's website that has an SSL-certificate, has had it for years, which has been working all that time. Now Firefox informs me:
"Firefox doesn’… (مزید پڑھیں)
I was going to look at a friend's website that has an SSL-certificate, has had it for years, which has been working all that time. Now Firefox informs me:
"Firefox doesn’t trust this site because its certificate isn’t valid for www.wuwei-school.nl. The certificate is only valid for: wuwei-school.nl."
Really?
I pretty sure there's nothing wrong with the certificate and I was taught that the "www" component is not important as a prefix for the domain name in a URL. It is just a shorthand code to show that the address is a URL.
Can Mozilla fix this issue? Or, at least, explain?
Thanks
Firefox's full message:
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Be careful. Something doesn’t look right.
Firefox spotted a potentially serious security issue with www.wuwei-school.nl. Someone pretending to be the site could try to steal things like credit card info, passwords, or emails.
Advanced
What makes the site look dangerous?
The site is set up to allow only secure connections, but there’s a problem with the site’s certificate. It’s possible that a bad actor is trying to impersonate the site. Sites use certificates issued by a certificate authority to prove they’re really who they say they are. Firefox doesn’t trust this site because its certificate isn’t valid for www.wuwei-school.nl. The certificate is only valid for: wuwei-school.nl.
What can you do about it?
Probably nothing, since it’s likely there’s a problem with the site itself. Sites use certificates issued by a certificate authority to prove they’re really who they say they are. But if you’re on a corporate network, your support team may have more info. If you’re using antivirus software, try searching for potential conflicts or known issues.
View the site’s certificate
Learn more about secure connection failures
Error Code: SSL_ERROR_BAD_CERT_DOMAIN
Aug 21, 2026 11:10:31 PM GMT+2
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