You tell that you are still not sure about {the difference between a "map" and a "layout"}.

A “map” (= Percussion MIDI Map) is a separate file (= not located inside your Finale document = not document specific).

Al the “maps” are stored in a specific folder.

From that folder the “maps” are available to all your Finale documents.

The “map” establishes a connection between MIDI numbers and percussion sounds (example: Hi Hat Foot on MIDI #44)

Finale comes with some useful Percussion MIDI Maps, and you will seldom (if ever) need to create/modify Percussion MIDI Maps.

If you create your own custom Percussion MIDI Map, and then send your Finale document to someone else, then you must also send your custom Percussion MIDI Map.

A “layout” is located and saved inside the Finale document (= document specific).

The “layout” establishes a staff position for each MIDI number (example: MIDI #35 - Bass Drum - in the lowest space, the ‘f’ position in Treble Clef).

Regarding your problem:

It sounds like there is something wrong either with your custom Percussion Layout or with the Library containing your Layout.

As a test (not as a solution) you could make a duplicate copy of the Finale document.

In the duplicate copy delete everything except the “pesky” Percussion Layout.

Then, save a Library of just that very Percussion Layout.

Try to load this special Library into other documents.

Thank you, Peter,

As always, a very thorough and helpful explanation!
:-)
Vanessa