Instrument names can be marked invisible but this is lost on save/load
Steps for reproducing it:
1) Create a score with more than 1 instrument.
2) Select an instrument name and make it invisible by pressing "V".
3) Save the file and close it
4) Open the file again. The instrument name you've made invisible is visible again.
It happens also on stable version 2.0.2.
GIT commit: 0bc5ff5