For a while many people who opened Outcore more than one time ended up not seeing their desktop (aka The Notorious Black Screen bug).
Solving it required asking users to navigate to Outcore.exe on their Windows filesystem, opening its properties, and disabling fullscreen optimizations in the compatibility tab. While this solution works, it is not ideal to ask users to go through all that. To make it worse, many users never even find out about this solution so they end up quitting.
This (I hope) changes today. I finally found the registry entry that remembers if fullscreen optimizations should be enabled/disabled, so I made the game force disable it when it launches. You may need to launch the game more than once to see it take effect.