This means that the game is having trouble loading up save and server files. Most likely this is because your Windows profile does not have read/write access to your documents folder (this is where your game save files are located). Try the following steps to see if these help resolve the issue.
1) Fully exit the game and close/exit out of Steam. Then restart your computer to see if that helps.
2) If not, ensure that when you are running Don’t Starve Together – that the Windows profile you are using has administrative access, and ensure that you are running the game as an administrator.
- For Windows 7/8: https://support.microsoft.com/en-us/help/14028/windows-7-how-log-on-as-an-administrator
- For Windows 10: https://www.cnet.com/how-to/how-to-check-if-your-windows-10-account-is-administrator/
3) Run Steam as an Administrator
- Fully close out of Steam and restart your computer.
- After restarting your computer, right-click on the Steam icon > select "Run as Administrator"
- Try launching the game after you have administrator access.
4) Run the Game as an Administrator
- Try running Don't Starve dontstarve_steam.exe as an administrator in your game folders (Steam\steamapps\common\Don't Starve Together\bin\dontstarve_steam.exe)
- Right-click on it and select "Run as Administrator"
5) If that fails, try creating another save directory (say c:\DontStarveTogether) and then launch the game with that as the save directory:
- In steam right-click the game in your library
- Select ‘properties’
- Click ‘Set launch options’
- Enter ‘-persistent_storage_root c:\DontStarveTogether’ (without the quotes)
- Close dialog.
- And the next one
- Launch the game.
Should you continue to encounter the issue, please post your issue as well as your log.txt file in our Don't Starve Together Bug Tracker forum.