If you're having trouble with startup, see the basic troubleshooting guide.
If you're still having trouble, start a thread in the Support & Bugs section of the forum (Official Forum | Steam Forum) or ask for help from the community on Discord.
If the support team helps, they will likely need to see your log file, so get a head start and follow these instructions to email them your log file.
Preview Versions
Preview versions (formerly "community tests") are sneak-peaks of upcoming releases. These preview versions are works-in-progress and are made available so the community can help with feedback and testing. These preview features are subject to change, may contain bugs, and may have stability and performance issues.
Note: Any previously saved simulations or objects from officially released versions of Universe Sandbox that are loaded in preview versions may look or behave differently than expected. Similarly, any simulations or objects that are saved in a preview version of Universe Sandbox may look different when they are loaded in other versions of Universe Sandbox. If a saved simulation or object looks different than expected, you can open the simulation or object in the most recent version of Universe Sandbox and resave it.
To opt-in to preview versions when they are available:
1. Exit Universe Sandbox
2. Right-click on the game title in your Steam Library
3. Click on ‘Properties’
4. Select the ‘Betas’ tab
5. Set the dropdown menu to ‘!preview-version’
6. Close the Properties window
7. Steam will now update Universe Sandbox to the preview version
8. Once updated, launch Universe Sandbox