Fix Firefox “The certificate is not trusted because it is self signed” error
If you want to visit a site and get a popup with this error in Firefox 3.5, what you have to do is this:
1. Type about:config in the address bar. From the window that appears, find the following line “browser.xul.error_pages.enabled”. If the value from the same line is false, then double click it(it will turn to “true”).
2. Enter the URL of the webpage that you wanted again, a window will appear offering you the option of adding an exception that allows you to view the website.
Adding an exception can also be done manually, following the steps:
1. Go to “Tools” menu and then “Options” .
2. Click on “Advanced”, then tab “Encryption” .
3. Click on the “View Certificates” button.
4. Select the tab called “Servers” from the window that appears.
5. Click on the button “Add Exception” (bottom right).