Nero MediaSuite 10: Nero SoundTrax. Can't access file

I have created a SoundTrax file/project using Nero MediaSuite 10.

I have opened and saved and opened and saved the file a dozen times before the project was completed.

I am now trying to open the file again, about a week later, and I get the following error message: “Unable to open the file which is referenced by the Nero SoundTrax Project.”

What gives???