Problem when loading a project created by pc on a Mac OS X

I use nuendo 6.5 to create a project on a pc. When I moved it to a Mac OS X computer in order to open it , I found the nuendo 6.5 for mac crashed .The same problem happened too with nuendo 6. There0 will be my greatest grace , if anyone can help me to solve this problem.

Tips: I found some manul notes in the Operation Manual which said:
“On Windows systems, file types are indicated by three letter file name extensions (such as *.npr for Nuendo project files).
On Mac OS X systems, it is not necessary to use file name extensions, since the file types are stored internally in the files. However, if you want your Nuendo projects to be compatible with both platforms, make sure that the “Use File Extension in File Dialog” option is activated in the Preferences dialog (General page). When this is activated, the proper file name extension is automatically added when you save a file.”
But I can’t find anything about" “Use File Extension in File Dialog” option is activated in the Preferences dialog (General page)."

Check Finder preferences, Advanced tab. Maybe this will help. “Show all filename extensions”.