Hi mllamu,
Zero Gravity is not part of the Factory Content of Padshop 2.
Please uninstall Zero Gravity via the Contol Panel. Redownload Zero Gravity from the Steinberg Download Assistant (Absolute 4 Collection). Then reinstall Zero Gravity and make sure to install everything for all users. There is a little checkbox to tick in the installation dialog of Zero Gravity. That should fix the problem.
Cheers,