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Your game should stay up to date on Steam but might not on other platforms. Make sure you're running the latest stable build of the game for all the latest fixes. If there is a bug fixed by a preview or development patch those are only available on Steam.
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Verification of Game Files
In Steam and other platform you can validate your game files. This will re-download any files that have been altered or deleted. In Steam, go to Properties of the game and select Installed Files tab to find the Verify Integrity of Game Files button. Press it and it will revalidate and download any files it needs to.
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