MOTU sometimes inserts code into the midnam files that Pro Tools doesn't recognize. If you are having trouble using a midnam file, open the file in a text editor and ook for any NoteNameList data (including any tags) in the .midnam file and delete it.
If you have patch lists from FreeMIDI/Galaxy or other editor librarians, you may be able to use an application called 'CherryPicker' to convert them to midnam files.
CherryPicker