This error will present itself with a message about a "client/server version mismatch - Bad Product Version", generally at some point in the process of attempting to load into the Persistent Universe. Should this happen, it means there is an issue with the game files on your computer and you will need to fully uninstall and then reinstall the game.
To ensure that all of the files are properly cleared out to start over with a fresh slate, follow these steps:
- Right click on the Windows icon and select Run.
- Enter and run %appdata% and click Ok. This opens Users\CurrentProfile\Appdata\Roaming. Delete the rsilauncher folder.
- Right click on the Windows icon and select Run again.
- Enter and run %localappdata% and click Ok. This opens Users\CurrentProfile\Appdata\Local. Delete the StarCitizen folder.
- In the file manager, navigate to (install drive)\Program Files. Delete the entire Roberts Space Industries folder.
- Clear your Trash/Recycle Bin. The amount of files deleted need to be cleared to save space.
Once the above steps have been completed, you can download and reinstall the game.