The page you are trying to view cannot be shown because the authenticity of the received data could not be verified.
   Please contact the website owners to inform them of this problem."

I keep getting an error message when I try to open most websites in Firefox. This includes the Canada Revenue Agency, which is as secure and up to date as any website can be. This is the error message: "Secure Connection Failed An error occurred during a connection to www.canada.ca. PR_END_OF_FILE_ERROR Error code: PR_END_OF_FILE_ERROR The page you are trying to view cannot be shown because the authenticity of the received data could not be verified. Please contact the website owners to inform them of this problem." This error message happens even when I get an update notice for Firefox and try to download the new version. What to do? So far I have reset the clock on my Mac.