DST closes in Start Up after opening as a little window and having a blackscreen

Unfortunately we are limited in the amount of assistance that we can provide as we don't have much information about your specific issue. If you have not done so yet, please check the link below, you should be able to find a resolution to just about every issue that won't allow you to play Don't Starve Together. Check that out here: https://support.klei.com/hc/en-us/articles/360029555352

If you are using a newer AMD Radeon or Radeon RX series graphics card, please follow the troubleshooting steps in our support guide for issues when running the game with a Radeon graphics card: https://support.klei.com/hc/en-us/articles/4411901338004

And please ensure that there are no programs running in the background that may interfere with or conflict with the games' and Steam's processes: https://support.steampowered.com/kb_article.php?ref=9828-SFLZ-9289 

If the game is not launching on Steam after you see the message "Preparing to Launch...." please follow the troubleshooting steps provided on Steam's Support page: https://help.steampowered.com/en/faqs/view/5814-D9A3-BE42-62DF

Should the issue persist after following all troubleshooting steps in the links we provided above, please provide your DxDiag.txt and Client_log.txt files. Please check this link for steps on how to find/generate these files: https://support.klei.com/hc/en-us/articles/360029881191