Steam updates any corrupted or missing files when you verify your game files, ensuring that the game has all the data it requires. Your game might be missing one or more files if it is glitching, ...

Verify the integrity of the game files on Steam, Epic, GOG Galaxy, Ubisoft Connect, Battle.net, Origin, Rockstar Games Launcher by following this tutorial.

To ensure that the integrity of your game files is intact, or to fix certain issues like Steam is already running error, you can let Steam verify it.

Free File Integrity Checkers & Checksum Integrity verifier tools to check file integrity of downloaded files in Windows using MD5 & SHA1 cryptographic hashes for files.