see this help article:

• https://support.mozilla.org/en-US/kb/secure-connection-failed-error-message

Your System Details shows;

Installed Plug-ins

Shockwave Flash 13.0 r0 Shockwave Flash 11.4 r402

Does this affect all sites (for example, this site) or only particular sites? Do you see any pattern to it?

This particular error message is very specific that it is a time issue, meaning either date, time, or time zone. So usually it is a system clock issue.

Another user reported this problem last week where it didn't seem to be a clock problem, but I don't think we discovered the cause of it in that thread. You could peruse it for possibly useful information: I can't get certain pages to load. How can I fix this?

hello, as jscher2000 mentioned it might also be caused by a wrong timezone - what result do you get at time.is (which will compare your time to an atom clock)?

You can also check the connection settings.

• Tools > Options > Advanced > Network : Connection > Settings
• https://support.mozilla.org/kb/Options+window+-+Advanced+panel

If you do not need to use a proxy to connect to internet then try to select "No Proxy" if "Use the system proxy settings" or one of the others do not work properly.

See "Firefox connection settings":

• https://support.mozilla.org/kb/Firefox+cannot+load+websites+but+other+programs+can