Action Menu Item (Custom Protocol Handler - OSX)

I’m attempting to set up an action menu item using a custom protocol handler on osx. There’s a great article and youtube video running through this but it doesn’t seem to be working:

Everything about setting up the apple script, updating the plist file, entering the url in ShotGird is all good. But when I attempt to pass in the arguments from ShotGrid using the “on open location this_URL” apple script step, the AMI still launches the application, but skips over the code nested in the “on open location” statement.

So essentially, I can an app successfully but can’t pass in any data from ShotGrid.

Any advice would be greatly appreciated. Thanks.