By default, the menu bar appears on all displays in macOS. You need to change this default to prevent the menu bar from appearing on your video projector output when using Isadora.
- Go to the System Preferences and choose "Mission Control"
- Uncheck the box next to "Displays Have Separate Spaces"
- Close the Preferences
- Choose "Log Out..." from the Apple Menu
- Log back in as you would normally.
This article has more information about optimizing up your computer for Isadora.