Display menu/Navigator bug
From forum post by tmwtp: //musescore.org/en/node/1237
Using WinXP Pro SP2 with MuseScore 1619
Steps to reproduce the bug: start MuseScore and uncheck the Navigator in the Display menu; close musescore; start musescore, the navigator appears even though if you open the display menu the navigator is unchecked. If you restart Musescore nothing changes, the Navigator is activated even though it is inactive in the display menu. To make it disappear you have to check it in the Display menu (at which point nothing happens to the Navigator) and then uncheck it (at which point it disappears). If you close & start musescore again the same problem appears.