Hi Navaira, I followed the suggestions on this page:
http://us.focusrite.com/answerbase/my-interface-isnt-showing-up-when-connected-to-my-mac and after rebooting, all was fine.
The first set of files to be deleted can be found by navigating to Mac HD > Library > Preferences > Audio. There should be two preference files in this folder:
com.apple.audio.DeviceSettings.plist
com.apple.audio.SystemSettings.plist
Any additional files in the Audio folder will likely be duplicates (which can often be the cause of the problem), you should delete these files as well.
The other preference file that can cause a similar problem is found in a different Library folder.
On OSX 10.7 and later, open Finder > click 'Go' at the top of the screen > Hold down the "Alt/Option" key and click on the Library folder > Preferences > delete 'com.apple.audioMIDIsetup.plist'
On OSX 10.6 and earlier, the User Library folder is not hidden and so can be accessed by navigating to Mac HD > [your username] > Library > Preferences > delete 'com.apple.audioMIDIsetup.plist'
Note: This filename is lengthened to 'com.apple.audio.audioMIDIsetup.plist' on systems running OSX 10.10 Yosemite.
There are 3 Library folders on a Mac so if you cannot see one of these files it’s worth double-checking that you are navigating to the correct one. After trashing these files restart your computer.
Hope you get it sorted. If not, I do find that Focusrite are very helpful and a quick email to them gets a prompt and earnest response. Cheers.