What happens when you try? Any error messages?

Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac=Options) key, and then starting Firefox. A small dialog should appear. Click Start In Safe Mode (not Refresh).

Is the problem still there?

Start your Computer in safe mode with networking. Then start Firefox. Try Safe websites. Is the problem still there?

Starting The Computer In Safe Mode;
Free Online Encyclopedia

i did that, and i am still having problems.

Can you please give more details about what happens when you try to open a page or follow a link? For example:

• Firefox does nothing
• Firefox displays a message like page not found or server not found
• Firefox displays an error of some other kind -- details please

It brings up server not found like this

I assume the sites will open in Safari or in Google Chrome. You probably saw one or both of these articles already but just in case:

• Firefox can't load websites but other browsers can
• Firefox and other browsers can't load websites

Is there any pattern to the URLs that do not work, for example, secure site addresses (HTTPS) versus regular site addresses (HTTP)?

I have already tried both. didnt work either

VannaGrace258 said

I have already tried both. didnt work either

Tried both other browsers, or tried both support articles??

If no browsers work with those sites, is it possible that your router (the box from your cable or DSL or fiber company) is blocking access? Sometimes they contain security or parental control software. Sometimes they need to be unplugged for a minute and plugged back in (power cycled).

You can try a different DNS server and disable IPv6 (check for other possible causes as well).

• http://kb.mozillazine.org/Error_loading_website

See also:

• https://support.mozilla.org/kb/troubleshoot-firefox-issues-caused-malware
• https://support.mozilla.org/kb/troubleshoot-SEC_ERROR_UNKNOWN_ISSUER

I fixed it by restarting my computer