If the following error is encountered:
Secure Connection Failed
An error occurred during a connection to simplegradebook.ca. The OCSP server suggests trying again later. Error code: SEC_ERROR_OCSP_TRY_SERVER_LATER
The fix is as follows:
Navigate to "about:config" in Firefox (i.e. type "about:config" in the URL address box at the top). Click through the silly "This might void your warranty" page. Warranty? Once you get to the config page, scroll waaaaaaaayyy down to find the following line (fortunately they are listed in alphabetical order).
security.ssl.enable_ocsp_stapling
Set the stapling to false. To set it to false just click on the line where it occurs.