hello craigbutcher, first please make sure that the date & time is set correctly on your system. if this doesn't solve the issue (or it is already set properly), a possible solution depends on different factors: * what is the '''error code''' shown under ''technical details'' on the error page? in case the error code equals ''sec_error_unknown_issuer'', please attempt to add an exception on the bottom of the error page & inspect the certificate (see the screenshot attached for instructions): * which '''issuer information''' does the certificate contain? thank you! [["This Connection is Untrusted" error message appears - What to do]]

Also, go to '''Mozilla.org''' and get the full install for the current version.