Curiously,

I have a project I have been working on for three years in Version 8. When I open in in version 10 (build 738) or 11 (build 701) I get the gray screen that Vegas has stopped working.

any idea what that is about.

The project has four nested projects in it as well as raw footage.

Thank you.

Try uninstalling the older versions.

Finish it in 8. Then upgrade to 11.