Solving self-signed certificate related errors in firefox

If firefox shows following error:

This site uses an invalid security certificate.
The certificate is not trusted because it is self signed.
(Error code: sec_error_untrusted_issuer)

without giving an option for creating exception then use following steps to solve the problem:

Open preferences
Go to Advanced -> Certificates -> View certificates
Got to Servers
Click Add Exception
Search for the site that is not opening and view its certificate. In details tab look at value for 'Issuer'
Add permanent exception for the certificate
Now go to Authorities tab (Next to servers) tab
Go to the issuer which issued previous self-signed certificate and edit trust for that issuer to identify websites.
Close all settings / preferences dialog boxes and try to open site again

Anonymous