That might be a bug due to a corrupt installation of Studio One (which can happen to any piece of software sometimes).
First I'd recommend trying to create a new song from the "Interfaces" tab.
1. open S1
2. Click "Create a new song"
3. Click the "Interfaces" tab (if you don't see this tab you need to finish the "activation" process - http://support.presonus.com/hc/en-us/articles/210049863--3-Studio-One-3-Software-Activation-Online-Computer- )
4. Select AudioBox USB (this will still work fine even though you have an iTwo)
If the issue persists then try uninstalling Studio One and reinstalling it.
If you're still having trouble I recommend opening a support ticket. Login at my.presonus.com , click "Support", then "Create a support ticket".