What Causes the “Content File Locked” Error on Garry’s Mod?

We investigated the issue after receiving numerous reports from users who were unable to play the game due to the error and devised a list of solutions which solved the error for most of our users. Also, we looked into the reasons due to which the error was being triggered and they are listed below. Now that you have a basic understanding of the nature of the issue we will move on towards the solutions. It is recommended for you to try these solutions in the specific order in which they are displayed in order to avoid any conflicts.

Solution 1: Allowing through Firewall

Sometimes the Windows Firewall blocks certain elements of the game from making contact with the server. Therefore, in this step, we will be allowing the app through the firewall. For that:

Solution 2: Allowing through Windows Defender

It is possible that the Windows Defender is preventing certain files of the game from being stored on the computer and is deleting them. Therefore, in this step, we will be adding an exclusion for the game in the Windows Defender.

Solution 3: Verifying Game Files

The game requires all of its files to be present and intact in order for all of its elements to function correctly. If a certain file is missing or has gone corrupt the game will not work properly and cause issues with the launch process. Therefore, in this step, we will be verifying the game files through the steam client. For that:

Fix: Garry’s Mod CrashingFix: Steam Content File is LockedFixes for Error Occured while Updating (Corrupt Content Files) in SteamAn error occurred while updating Super People? Try these fixes Fix  An Error Occurred while Updating Garry s Mod  Content File Locked  - 34