In some cases, after installing Mac OS X v10.6 Snow Leopard and Final Cut Studio 3, Motion 4 projects can be created and saved, but these projects cannot be opened.

Motion projects from any previous version will also not open.

The following warning will appear: The document “Project.motn” could not be opened.

Το Motion 4, μπορεί να μην είναι σε θέση να ανοίξει τα πρότζεκτς

Programs
Motion 4.0

Solution

To address this issue, make sure that Motion is not running. Next, open Terminal (located in /Applications/Utilities), and run the following command:

sudo touch /Applications/Motion.app

This command can only be run under a user account with administrator access.