Hello,
I have set hide empty staves to “always”, but the empty piano staff on the first system does not disappear, probably because it has an independent key signature set with alt+return. When I delete the key signature so it goes back to what the other staves have, the piano staff is hidden.
Is there a better way of doing this? Or should I just resort to only changing to my desired key sig when the piano starts to play?
Thanks
LAE
I think you found the answer 
But look what happened when I did that…!
It looks like there are two key signature changes… What do you see when you turn the Key Signature signposts on, in the view menu ?
I deleted it and added it again, I only created one.
Show key signatures signposts is activated, but I don’t see any of those anywhere in the score. Do they show for you?
You are right, signposts do not show up when the key signatures are assigned with alt enter.
I tried to do the same thing you did, and I end up with the same problem
Yes, this is a problem that affects independent time and key signature changes when the system they occur on is hidden. This is on our list of bugs to fix in future, but I can’t say for sure when it will be fixed.
For me, no signposts for key signature show at all, no matter how I have added them. How do I make them visible?
Signposts for key signatures will only appear if the key signature shows no accidentals, or (if memory serves) if the instrument itself shows no key signature (e.g. ‘Horn in F (no key)’).
Aha!