The #1 troubleshooting step for any problem with Pro Tools is to:
Trash DigiSetup (located in the Preferences folder inside the System Folder or just in the System Folder)

Trash DAE Prefs (located in the DAE Prefs folder inside the System Folder)

Empty the trash and then RESTART the Macintosh.

Don’t worry. Pro Tools will create new preferences files when the software is launched again and used. Careful: trashing the Pro Tools preferences file will change some of the functional parameters that you have previously set. These will have to be reset manually (that’s why we don’t recommend that you trash the Pro Tools preferences). Also, trash the contents of the DAE prefs inside the DAE prefs folder, not the folder itself and certainly do not trash the DAE folder!

This procedure is useful when changing your setup from a Digidesign 888 or 888/24 interface to an AD-8000 or back. Also, whenever there is a problem while using the AD-8000, the first troubleshooting step should be this one. It should be performed every time that a change is made in hardware or software setups.