Can you attach a screenshot? *http://en.wikipedia.org/wiki/Screenshot *https://support.mozilla.org/kb/how-do-i-create-screenshot-my-problem Use a compressed image type like PNG or JPG to save the screenshot. Is this with a secure https connection? If that is the case then check out why the site is untrusted (click "Technical Details to expand that section) and if this is caused by a missing intermediate certificate then make sure that you install all required intermediate certificates on your servers. You can retrieve the certificate and check details like who issued certificates and expiration dates of certificates. *Click the link at the bottom of the error page: "I Understand the Risks" Let Firefox retrieve the certificate: "Add Exception" -> "Get Certificate". *Click the "View..." button and inspect the certificate and check who is the issuer. You can see more Details like intermediate certificates that are used in the Details pane. If "I Understand the Risks" is missing then this page may be opened in an (i)frame and in that case try the right-click context menu and use "This Frame: Open Frame in New Tab".