After enabling client DPI-SSL on the SonicWall it is necessary to install the DPI-SSL client certificate on all Macs to avoid the security error presented by installed applications.
In order to download and install the certificate, follow these steps:
NOTE: Firefox has it's own certificate store. If firefox is being used, please import the certificate into Firefox as well according to this knowledge base article How to manually import the Client DPI-SSL CA certificate into Firefox browser