General - Mac OS X 10.11 And Lower Security Certificate Fix
If you are using an older version of OS X (Version 10.11 or lower) and for any reason are unable to update your operating system, you may have experienced errors when accessing DPG and other websites. This is due to an expired security certificate. If you're using the affected operating system and see a page displaying the "This Connection Is Not Private" error, watch the video below to learn how to correct the issue.
To avoid these kids of problems, it's always best to keep your OS updated to the latest version where possible.
Link to download new certificate as described in the video.
After installing the updated certificate we recommend using Google Chrome as your browser, as it is frequently updated unlike older Safari versions.