I just tried it on a Mac in Finale 26, pretty simple. I created an expression "harmon mute", I didn't change any playback parameters. I assigned it to a note and it changed the sound to a harmon mute. Then I created another expression "open", assigned it to a note and it changed back to the open sound.

If this doesn't work for you, then make sure you have the NotePerformer human playback preferences installed. and selected.

What Jeffery says. If that isn’t working for you, Wallander Support is fairly responsive via email. One thing to check is if you’re running 3.3.2 and update if not.

There’s more than one way to call up NP, directly or in the Aria Player.

Thanks for your help, Gents!

I solved the problem by opening up a new score and transferring the notes.  The "harmon" and "open" expressions worked perfectly on the playback.

I'm suspecting the problem came from me opening the previous version in a big band template, but I'm not sure.

Best,

Mark