You will want to take a look at the following article from Focusrite:
https://support.focusrite.com/hc/en-gb/articles/115000166845-Second-Generation-Bus-Powered-Scarlett-Interfaces-and-macOS-Sierra-10-12-2
Here is a link to Focusrite's Sierra compatibility page:
https://support.focusrite.com/hc/en-gb/articles/211671129-Are-Focusrite-products-compatible-with-macOS-Sierra-
You may want to reach out to Focusrite on this issue. Below are some basic troubleshooting steps for Studio One.
You may want to try re-installing Studio One and deleting your settings files from the program. To re-install Studio One, simply delete the app from the Applications folder and then download/install the latest version once more. Below are instructions on deleting your settings:
1. Go to Help>Open Settings folder.
2. Copy the contents of the folder over to a folder on your desktop.
3. Close S1 and delete the contents of the settings folder with the exception of the user.license file as well as the "Extensions" folder.
4. Open S1 and go to Studio One>Options (Preferences on a Mac) to reconfigure your settings.
5. 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.
