Forgive me for pointing out the obvious, but are you sure that both programs are looking in the same directory? Sometimes, after an upgrade the software goes back to looking for files in the programmed default directory instead of the directory where I keep all my scores and expect HA to always look. It always dumbfounds me until I realize what happened (again!).
Le silence éternel des espaces infinis m'effraie. Church musician
Thanks, Paul. The problem has been "solved" via regular e-mails. Apparently, there were two issues : one was the choice of folders and the other one the extension of the exported files that didn't appear to be "standard" (.myr).