When you load presets into Studio One, they are loaded from your Documents>Studio One>Presets folder by default. You may want to verify that there is a "presets" folder in your user data folder which is defined under Studio One>Options>Locations>User Data.
If you would like to remove the settings files from Studio One, here are instructions:
Go to Help>Open Settings folder.
Copy the contents of the folder over to a folder on your desktop.
Close S1 and delete the contents of the settings folder with the exception of the user.license file as well as the "Extensions" folder.
Open S1 and go to Studio One>Options (Preferences on a Mac) to reconfigure your settings.
Test to see if the problem is resolved. If it is not, please feel free to copy your settings files back over from the backup that you created in step 2.
*If you are missing presets or Sound Sets after doing this, simply double-click one of your Sound Sets under Documents>Studio One>Sound Sets.
If the problems persist, please try uninstalling and re-installing Studio One. Make sure that you download a new installer from within your my.presonus.com account. If you still have any problems, please feel free to submit a support ticket from within your my.presonus.com account.