I've just installed FM-12 Advanced, only to read that it suggests (requires?) converting my FM-11 files to FM-12. Does this mean that my five other users, using FM-11 to enter input to my FM files would have to be upgraded to FM-12 in order to access the converted FM-12 files?

Does this mean that my five other users, using FM-11 to enter input to my FM files would have to be upgraded to FM-12 in order to access the converted FM-12 files?

Correct. Filemaker 12 is file format change.

That's an expensive solution. How about an approach wherein some of the features from FM-12 are copied and pasted into FM-11?

How about an approach wherein some of the features from FM-12 are copied and pasted into FM-11?

Impossible.

If you're talking about the graphical things you create in 12, you can copy those items back into 11.

Trying to communicate one with the other is not possible because they were written in different languages, so the conversion process is a one-way street, however it does not harm your version 11 files.

Lee