Black screen after turning full screen on.

First things first, please ensure that your graphics card drivers have been updated to the latest version. Same goes with your monitor's drivers. 

Also Don't Starve Together's settings file is located in your documents folder at C:\Users\{User Name}\Documents\Klei\DoNotStarveTogether\client.ini - you can open and edit this using a text editor (line notepad), and save when finished.

Should editing the file not resolve the issue, delete your client.ini file to see if that helps. If the issue persists, please provide us with your DxDiag.txt and client_log.txt files.

Hello.

How are we going investigating this problem? This is behaviour I have had for a while on my dual monitor machine. Full screen worked earlier in the together beta, then at some point it would have this black screen, unable to use my machine without restarting it state. Audio would still play but could not close the application or switch to task manager or desktop to shut down. Don't Starve worked fine.

This problem started for me during the beta period back in maybe April. If I tried to use the continually updated environment it had this behaviour. I solved this by deleting local content and applying a steam backup from an install on another machine.

For me this problem was somewhere in the incremental update process.

Hope this is solved for you.