Why is Auto-Key's "Send to Auto-Tune" button not working?

Auto-Key's "Send to Auto-Tune®" button is designed to automatically transmit Auto-Key's detected Key and Scale setting to every compatible instance of Auto-Tune in your session.  In the event that you find Auto-Tune's Key and Scale settings do not update to match Auto-Key's after pressing the "Send to Auto-Tune" button, there are a couple of things you can try to resolve the issue:

Make sure the "Enable Auto-Key Key/Scale Detection" setting is enabled in Auto-Tune:

1. Open your Auto-Tune plug-in, click on the Settings drop-down menu and click on Preferences. 

2. Make sure that the "Enable Auto-Key Key/Scale Detection" setting is enabled (checked).  If you don't see a checkmark next to it, click on it to enable this setting.

3. Make sure the "Save as Default" checkbox is checked.

4. Click "Save" to save your settings.

Once Auto-Tune's "Enable Auto-Key Key/Scale Detection" setting is enabled, Auto-Key's "Send to Auto-Tune" button should work as expected.

Repair Disk Permissions (Mac only):

If you followed the above instructions to ensure that the "Enable Auto-Key Key/Scale Detection" setting is enabled in Auto-Tune, but are finding that pressing Auto-Key's "Send to Auto-Tune" button still does not update the Key and Scale settings in Auto-Tune, repairing your Mac's disk permissions should resolve the issue.  

On a Mac, you can do this by opening up the Disk Utility application.  Then select your main system hard drive that your applications are installed on and click on the "First Aid" button.  (If you're on an older Mac OS prior to OS X 10.11.6, you can select the "Repair Disk Permissions" option in Disk Utility instead).