Loading files issue

Hello,
I have been working in a new score. I created parts for some instruments and wrote its melody.

I saved the file and now, when I open the file I only see one of those parts of one of the instruments. I do not see other parts!!!

I suffered this issue in the past but closing the file and opening it again was solved. But now, it does not work.

Please, do you know if there is any way to restore my file or if I doing something wrong saving my files?

Thank you.