If Firefox can't access a secure site (one that starts with https:) you will see an error page with the heading, Secure Connection Failed, and a message about the error. This article will describe some of these error messages.

• If you see this heading without accessing a secure site, see Fejlsøg udvidelser, temaer og hardwareacceleration for at løse almindelige Firefox-problemer.
• If you don't see this heading, see Websteder indlæses ikke - fejlsøg og ret fejl.

SSL protocol has been disabled

If you see this error, see Aktiver SSL for at rette Firefox fejlmeddelelsen Kan ikke oprette sikker forbindelse.

The site uses an older, insecure version of the SSL protocol

If you see this error, see Firefox cannot connect securely because the site uses an older insecure version of the SSL protocol.

Certificate warnings

Firefox uses certificates on secure websites to ensure that your information is being sent to the intended recipient and can't be read by eavesdroppers.

Certificate will not be valid until (date)

This error can occur if your computer clock has the wrong date, in which case the date given in the error message will be in the past. To fix the problem, set your system clock to today's date and time (double-click the clock icon on the Windows Taskbar).

The certificate expired on (date)

This error occurs when a website's identity certification has expired.

This error can also occur if your computer clock has the wrong date. To fix the problem, set your system clock to today's date and time (double-click the clock icon on the Windows Taskbar).

Certificate is only valid for (site name)

This error is telling you that the certificate sent to you by the site is actually for another site. While anything you send would be safe from eavesdroppers, the recipient may not be who you think it is.

A common situation is when the certificate is actually for a different part of the same site. For example, you may have visited https://example.com, but the certificate is for https://www.example.com. In this case, if you access https://www.example.com directly, you should not receive the warning.

The certificate is not trusted because the issuer certificate is unknown

The file cert8.db in your profile folder may have become corrupted. Delete this file while Firefox is closed.

1. Åbn din profilmappe:

   • Klik på menuknappen , klik på Hjælp, og klik så på Mere teknisk information.Åbn menuen Hjælp, og vælg Mere teknisk information. Fanebladet Teknisk information åbnes.
   • Klik på knappen Åbn mappeVis i FinderÅbn mappe ud for ProfilmappeProfilmappe i afsnittet Programinfo. Et vindue, der indeholder din profilmappe, åbnes. Din profilmappe åbnes.
   Bemærk: Hvis du ikke kan åbne eller bruge Firefox, så følg vejledningen i Find profilen uden at åbne Firefox.

2. Klik på menuknappen , og klik så på Afslut.Klik på Firefox-menuen øverst i vinduet, og klik så på Afslut Firefox.Klik på menuknappen , og klik så på Afslut.
3. Click on the file named cert8.db.
4. Press command+Delete.
5. Restart Firefox.
   cert8.db will be recreated when you restart Firefox. This is normal.

The certificate is not trusted because no issuer chain was provided

You may have enabled SSL scanning in your security software such as ESET or BitDefender. Try to disable this option.

The certificate is not trusted because it is self signed

or

Self-signed certificates make your data safe from eavesdroppers, but say nothing about who the recipient of the data is. This is common for intranet websites that aren't available publicly.

The certificate contains the same serial number as another certificate

This error alerts you to the fact that the certificate the page you're visiting uses has a serial number identical to one you've already accepted. This warning cannot be bypassed using the method below. For more information and for instructions on how to work around this message, see the Certificate contains the same serial number as another certificate article.

The OCSP server has no status for the certificate

If you see this error, see The OCSP server has no status for the certificate.

Bypassing the warning

You can tell Firefox to bypass these certificate warnings. You should only bypass the warning if you're sure that the site is legitimate. Legitimate public sites will not ask you to do this. An invalid certificate can be an indication of a web page that will defraud you or steal your identity.

1. On the warning page, click Or you can add an exception....
2. Click Add Exception.... The Add Security Exception dialog will appear.
3. Click Get Certificate.
4. Read the text describing the problems with this site.
5. Click Confirm Security Exception if you want to trust the site.