Go to https://forum.percussa.com/c/ssp-software-updates
and download the latest software update (1409) and the latest image file update (2307).
Use the instructions here in the forum to write the image file to the card. After that, put the latest software update on it. It will overwrite the SYNTHOR file when you unzip it onto the card in the BOOT partition.
As @2disbetter says, you don’t need to download all the updates. Just the latest one.
Make sure you backup your samples and presets folders from your card before you write the image to it. Once you write the image to the card the entire card will be erased and you will lose all your files unless you made a backup.