parts created on Mac AC9 not working on Win AC9

[tsturm]

I created a library of objects using the Mac verison of AC 9.

Now I am using a windows version of AC 9 at work.

Problem is the parts do not load. In fact when I load the parts, the application crashs. If I try to open a single part, I get a message about this part being an unkwon version. However, see the image, the part says it is a drawing symbol done in version 20.

What is going on here? Why do parts made on the Mac not work in the Windows version?

Can it be the location I am reading the file from is moved from Windows to Mac and back again? USB flash drive.