What happens if you erase the horn track and 'Save As' another name (then open the new file)?
What happens if you export the horns to wave file (Audio menu) on their own?
Can you open those?

Have you tried highliting the whole track and using 'Track-Consolidate Audio'?
Maybe regeneration of this RT has a quirk.


I do not work here, but the benefits are still awesome
Make your sound your own!