We require using the utility provided by the SD Card Association. There are installers for Mac and PC available from their site:
Using this utility is the only way to ensure that your SD Card will be formatted for optimum multi-track recording. Using built-in OS formatting tools in Windows or OS X will not suffice as the data is not fully erased using these utilities.
NOTE: This update will take approximately 30 minutes and should be done before any recording session that will record all 34 tracks onto the SD Card at once.
On Windows Systems
Launch the program and select the options shown below
On Mac Systems
Launch the program and select Overwrite Format and the "Logical Address Adjustment" Option as shown below
Once your card is formatted, the following video will explain how to begin an SD Card recording on your Series III mixer: