How to Fix Dev Error 841 in Modern Warfare 3

The Dev Error 841 often occurs while playing Ground War mode in Modern Warfare 3, indicating that the error is triggered by something specific to this mode. Even after addressing this error, you may still encounter crashes. If this is the case, it likely stems from a server issue that is the root cause of the problem.

Given that the error primarily occurs in Ground War mode, it suggests that the underlying issue is server-related. Beyond the server problem, the error could also arise from the telemetry feature being enabled or from corrupt game files.

If the error originates from server issues, there’s little you can do other than wait for the developers to resolve the problem. However, if your game settings or game files are the source, you can attempt to rectify this by utilizing the following methods.

It’s advisable to restart your device before altering settings or files, as this can resolve bugs that might be causing the error.

1. Turn Off Telemetry

Telemetry provides a User Interface (UI) for packet loss, ping, FPS (Frames Per Second), server latency, and more. Although typically beneficial, this feature can lead to Dev Error 841. Therefore, disabling telemetry could potentially resolve the error.

  1. Navigate to Settings > Interface.
  2. Scroll down to the Telemetry section.
  3. Disable all the options under Telemetry.
  4. After doing so, verify if the error has been resolved.

2. Repair the Game Files

Corrupted game files might also contribute to error code 841. It’s fortunate that such corruption can be addressed.


  1. Launch Steam and go to your Library.
  2. Right-click on Modern Warfare 3 and choose Properties.
  3. Select Local Files and click Verify the integrity of game files. This process may take several minutes.
  4. After the files are verified, start Modern Warfare 3 to check for the error.

  1. Open the Launcher and select Games from the menu.
  2. Choose Modern Warfare 3 from the list of games.
  3. Click on the Gear icon adjacent to the Play button.
  4. Opt for Scan and Repair from the dropdown menu.
  5. Select Begin Scan and await the completion of the file scanning and repair process.
  6. Once completed, open Modern Warfare 3 and check if the error has been addressed.

3. Reinstall Modern Warfare 3

If repair attempts fail, consider reinstalling the game. This will remove any corrupted files, ensuring that neither these nor misconfigured settings are causing the error.


  1. Access Steam and proceed to the Library.
  2. Right-click on Modern Warfare 3, navigate to Manage, and select Uninstall.
  3. Confirm by clicking Uninstall again.
  4. Reinstall Modern Warfare 3.
  5. Finally, launch the game and check for the error.

  1. Launch the Launcher and go to Games.
  2. Choose Modern Warfare 3 from the listed games.
  3. Click the Settings gear next to the Play button.
  4. Click Uninstall and confirm by selecting Uninstall again.
  5. Reinstall Modern Warfare 3 and verify whether the error is resolved.

4. Server-Side Issue

As previously mentioned, Dev Error 841 is often due to a server-side issue. Unfortunately, this means there are no actions we can take other than waiting for the developers to address the problem. Meanwhile, you can contact the Modern Warfare 3 support team by submitting a ticket. They can offer guidance after evaluating your situation.

Moreover, you can check the official Twitter account of Call of Duty for updates related to the issue. Alternatively, community forums such as Reddit may provide insights into whether other players are experiencing the same problem. Finding other affected users indicates that the issue is indeed server-side and likely to be resolved by the developers in due time.


Hamza Mohammad Anwar

Hamza Mohammad Anwar is an intermediate JavaScript web developer with a focus on developing high-performance applications using MERN technologies. His skill set includes expertise in ReactJS, MongoDB, Express NodeJS, and other related technologies. Hamza is also a Google IT Certified professional, which highlights his competence in IT support. As an avid problem-solver, he recreates errors on his computer to troubleshoot and find solutions to various technical issues.