Then its most likely indicative that due to your monitor setup and how the game currently does its graphics settings it absolutely bungled your settings.

But dont fret simply navigate to:
%userprofile%\AppData\LocalLow\Crema\TemtemSwarm
And delete the Graphics.dat file.

Once you've done this the game will regenerate a new Graphics.dat that should allow you to once more see something other than the unblinking VOID

This guide is primarily for the previous issue since its the one i had to fix myself, but if you are running into a different issue you could try and verify your game files, or worst case simple uninstall and reinstall

• Go to Library
  
• Rightclick the game or click the cogwheel on the game view
  
• Go to local files
  
• verify integirty

If you found another way to fix blackscreen issues ideally leave a comment here, I made this Guide because its a lil bit more visible than leaving info strewn across a myriad of disccusion topics.
Or if you already had an issue yourself and know of another fix do leave that down below.

As a final word of caution DO NOT delete your save file, unless you are absolutely sure nothing else worked, and even then i'd first ask people on the discussions or discord for help first.
And even then, back up your saves first.