If all your displays go black when opening Mediashout, or after switching to 2 or 3 display mode after opening it, it could be a couple of possible things.
One would be simply that the control screen and main program and/or stage displays are switched (they are receiving a video signal that should be going to one of the other screens, etc.)
To fix this, you would press CTRL + ALT + 1 to put Mediashout into 1 Display mode again. Then, you can go to the Settings tab and the General Settings button, then to Displays, and toggle the displays until they are correctly matched up with the outputs you want (Control will be your computer monitor for the operator to see, Main Display will be your congregation on your projector, TV, etc., and Stage Display will be the confidence monitor/display for your musicians, choir, singers, pastor, etc.)
Once you have set these correctly, you should restart your computer. Once that is done, go back into Mediashout then go to the Settings tab and change the drop down box from 1 Display to 2 or 3 Displays depending on your setup, and it should now be correct. If not, try until you find the right settings using the method above.
If this does not resolve the issue, it could be that your video card is incompatible or at least needs the drivers updated. To check the date of your video card drivers, on Windows 10, right click the Window/start button and click "System" then click "Device Manager" on the top left of that window. Under "Display Adapters," right click your video card and click "Properties." From there, view the "Driver" tab and view the date. If older than a couple months, you should check the manufacturer website (Nvidia, ATI, etc) for updated drivers. Do NOT use the update driver button in Windows.
Note: We recently have created a Display Setup Tool to help you get your MediaShout screens setup properly. Here is a link to this Tool:
https://support.mediashout.com/556638-Display-Setup-Tool-for-MediaShout-6