If ProPresenter is hidden behind your Output or Stage Display when you open the program or when you enable one of those outputs, it only takes a few seconds to fix. The steps below will walk you through each possible scenario first with the fix at the end.
You open ProPresenter and the screen goes black.
If you open ProPresenter and the screen immediately goes black (or other solid color), don't worry, this just means your output screen has moved. Generally this is caused by disconnecting your external display from your computer while ProPresenter is still open. This can happen if the program is running or if the computer is in standby, but ProPresenter was still open.
You enable your output and it comes up on your computer instead of your external display.
This can happen if you don't have an external display attached and you're trying to preview your slides, or if your Output isn't assigned properly in ProPresenter's Display Preferences.
You enable Stage Display and it comes up on your computer screen or audience screen.
Similar to the one above, if your Stage Display isn't assigned to the proper display, it will show up where you don't want it to. If you only have two screens (computer plus one output) then you probably aren't using Stage Display. It will also have to be assigned to one of those two displays even if it is inactive. If you have three displays, it may show up on your computer screen or the screen your audience sees if it isn't assigned correctly.
Fixing your Display settings
In each instance where your display opens on your computer screen, you will see a gray button with an 'x' in the lower left corner when you move your mouse. You can click on this button to close the display. You can also use Command-1 (Mac) or Control-1 (Windows) to turn off the primary output. Command-1 and Control-2 are for Stage Display. These shortcuts can toggle either display on or off regardless of which screen they are assigned to.
Once you have turned the display off and you can see ProPresenter again, you may need to adjust your display settings. If you normally use a second display with your computer, connecting to the display while ProPresenter is closed should automatically put the output and stage display back where you had it. If the display settings don't update properly, or you need to move displays around, open ProPresenter Preferences and go to the Display tab. Preferences can be opened by pressing Command-comma (Mac) or Control-comma (Windows) or by clicking on the ProPresenter menu and selecting Preferences.
The two animations below show the common setups for two and three screen scenarios.