Sorry to hear about the recent issues you have been experiencing.
A Studio One 3.5.1 patch was just released this morning.
Please delete your Studio One settings and reinstall Studio One 3.5.1, then reconfigure the FaderPort.
1. Quit Studio One
2. Click Start and type %appdata% [Enter] to open the Roaming folder.
3. Open PreSonus/Studio One 3
4. Copy the contents of the folder to a folder on your desktop for use as a backup.
5. Delete all files and folders except for the user.license file
6. Go to Control Panel > Programs and Uninstall Studio One
7. Log in to My.Presonus.com and download Studio One 3.5.1 and install. Reconfigure your settings.
*If you are missing any Sound Sets after doing this, simply go to Documents>Studio One>Sound Sets and double-click one of the files.
If the issue persists, please submit a ticket to technical support.