Did some more tests this morning. Definitely broken by X3d, and moreover it's broken for old as well as new post-X3d work.
Steps:
- Start a project, put in some MIDI notes on some tracks
- Or, import a commercial MIDI file
- Click the Mute button on one or more tracks.
- Save the project as a MIDI file type 1 (i.e. multitrack)
- Close project
- Reopen project from the above MIDI file
- Muted tracks no longer muted
I can work around this by deleting the tracks before saving but this could be dangerous if I inadvertently save with the tracks deleted.
This is a big issue for me.