Template crashes MuseScore | MuseScore

I created a file for use as a Template. However, whenever I try to load it, MuseScore crashes. Here’s what I’ve done:
FIRST: “save as copy” the normal MuseScore file in /documents/MuseScore4/Templates folder. Then I closed the file.
SECOND: File –> New–> Create from Templates –> My Templates –> “Hall Template” –> Done
….and down goes MuseScore.
The only other template I’ve written opens fine. Can anyone see what’s wrong with this one? I hope it’s a simple fix. And I certainly want to know if I’ve done anything obviously wrong before I move on to create other templates.
I’m on Windows 11 Pro, running the latest version of MuseScore4. Thanks in advance!