If you are having a problem with your Nektar MIDI controller not showing up in Studio One 3 after installing or updating Studio One, you will need to install the Nektar software once more. The software from Nektar must be installed after you install or update Studio One 3. For more information on this issue, you will want to visit the following link from Nektar's web site.
http://support.nektartech.com/s.nl/ctype.KB/it.I/id.1606/KB.1129/.f?category=8