Fix Modern Warfare 3 (MW3) Dev Error 6015

Call of Duty franchise has been a part of the first-person shooter special task force-type gaming series in the community for over a decade. With every release of the Call of Duty part and its successor, fans are getting indulged a lot. However, the Call of Duty developers fall short when it comes to stability or bug-free experience. Even the COD Modern Warfare III (2023) title has some dev errors like the previous generations such as the Modern Warfare 3 (MW3) Dev Error 6015.

Affected players have criticized the recently launched MW3 game due to its multiple bugs and issues out of the box. Encountering Dev Error 6015 isn’t a new thing because the Modern Warfare 2 title has gone through the same error previously. The specific error is frustrating enough to deal with as it affects the overall performance and experience of the game. If you’re also encountering the same dev error on your computer then don’t worry. You can consider a few workarounds below to fix this issue.

Fix Modern Warfare 3 (MW3) Dev Error 6015

Fix Modern Warfare 3 (MW3) Dev Error 6015

As per several reports, the dev error 6015 appears quite often whenever MW3 players try to launch the game on the respective platform. There might be some potential reasons applicable behind this error such as an outdated game version, corrupted game files, outdated graphics drivers, fullscreen optimization issues, conflicts with the in-game graphics settings, playing in fullscreen display mode, issues with the server status, and more which are quite common these days.

Though developers haven’t provided any official fix about the same, we’ll recommend our readers to go through the troubleshooting methods below that should come in handy. Make sure to follow all steps until the problem gets fixed. So, without further ado, let’s jump into it.

1. Restart the Gaming Device

First of all, you should reboot the gaming device at your end to clear out potential glitches of the system or game. This specific trick did come in handy for a lot of affected players.

2. Run COD MW3 as an Administrator

You should run the Call of Duty game executable app as an administrator to avoid user account control regarding privilege issues. The chances are high that your game application is somehow getting blocked by the system admin permissions. To do this:

  • Right-click on the COD MWIII.exe app on your PC.
  • Now, select Properties > Click on the Compatibility tab.

  • Enable the Run this program as an administrator option.
  • Click on Apply and select OK to save changes.

3. Check for Activision Online Services

You can also try checking the Activision Online Services by following the steps below to ensure there is no issue with the server status. Sometimes server status regarding issues might also trouble you with the multiple in-game challenges.

  • Visit the Activision Online Services page to check it.
  • Select the drop-down menu > Click on Call of Duty: Modern Warfare III from the list.
  • If you’re seeing All Platforms ONLINE then it indicates there is no issue with the game servers at that moment.
    • You can also click on the Refresh link to manually refresh the page.

However, if you’re seeing server issues then wait for a couple of hours to check for the same. In case, the services are running fine then head over to the next method.

4. Update Call of Duty Modern Warfare 3

In some cases, an outdated game patch version can trouble you a lot due to stability issues or bugs. So, it’s recommended to check for the game updates manually by following the steps below.

  • Open
  • Click on Game Library > Choose Modern Warfare III.
  • Now, click on the cog wheel icon.
  • Select Check for Updates.
  • Make sure to download & install the update, if available.


  • Open Steam > Go to Game Library.
  • Right-click on Modern Warfare III.
  • Select Properties > Click on Updates.
  • Head over to Automatic Updates.
  • Select Only update this game when I launch it.
  • It’ll automatically install updates whenever available.

For PlayStation:

  • Head over to the PlayStation home screen.
  • Head over to Games > Select Call of Duty Modern Warfare III game.
  • Press the Options button on the controller.
  • Select Check for Update.
  • If an update is available, follow the on-screen instructions to install it.
  • Wait for the update to complete and then reboot the console.

For Xbox:

  • Press the Xbox button on the controller to open the guide.
  • Go to My games & apps > Select See all.
  • Then head over to Games > Select COD Modern Warfare 3.
  • Press the Menu button > Select Manage game and add-ons.
  • Now, hit Updates > If there’s an update available, select Download and Install.
  • Wait for the update to install and reboot the console.

5. Scan and Repair the Game Files

Sometimes corrupted or missing game files on the PC might also trouble you while starting the game. It’s always better to verify and repair the game files by following the steps below on your PC to avoid errors.


  • Open > Click on Modern Warfare III.
  • Select the Cog Wheel icon next to the Play button.

  • Now, select Scan and Repair > Wait for the repair to complete.

For Steam:

  • Open the Steam client > Go to Library.
  • Right-click on Modern Warfare III in your library.
  • Go to Settings and select Properties.
  • Click on Local Files > Select Verify integrity of game files.

  • Wait for the process to complete.

6. Disable Fullscreen Optimizations

Well, disabling the fullscreen optimizations for the specific game application might also help in resolving the compatibility issues. To do that:

  • Right-click on the CallofDuty MW3.exe file.
  • Select Properties > Click on the Compatibility tab.
  • Enable the Disable fullscreen optimizations option.
  • Click on Apply and then OK to save changes.

7. Run Modern Warfare III in Windowed Mode

Even running the Call of Duty Modern Warfare III game in the windowed display mode can reduce the startup crashing issue or graphical glitches in most scenarios. So, if you’re running the game in fullscreen mode, try using the windowed mode by following the steps below.

  • Launch COD Modern Warfare 3 > Open the in-game Options menu.
  • Navigate to the Graphics or Display settings.
  • Select Windowed or Windowed (Borderless) from the list.
  • Save the changes and try playing the game again.

Please Note: In case, the game is already running in fullscreen then hit the Alt+Enter keys to switch between fullscreen and windowed mode easily.

8. Adjust Modern Warfare 3 Graphics Settings

Another thing you can also try is to change some of the in-game graphics settings by following the steps below. It’ll eventually help in reducing the graphical glitches or other graphics-related issues up to some extent.

  • Open the Call of Duty Modern Warfare 3 game.
  • Go to Options from the main menu.
  • Select the Graphics or Video settings.
  • Adjust the following settings to the minimum values:
    • Screen ResolutionLow or Normal.
    • Texture ResolutionLow or Normal.
    • Shadow Map ResolutionLow.
    • Particle EffectsLow.
    • Depth of FieldDisable.
    • Motion BlurDisable.
  • Apply the changes and check for the issue further.

9. Update the Graphics Driver

You should try to update the graphics driver manually by following the steps below. It’ll eventually fix an outdated graphics driver version or corrupted driver. So, if you’re using an outdated graphics driver on your system then try updating the same.

Recommended Update:

  • Press the Win+X keys > Click on Device Manager from the list.
  • Double-click on Display Adapters.
  • Right-click on the dedicated graphics card that you use.

  • Select Update Driver > Click on Search automatically for drivers.
  • If an update is available, it’ll automatically download & install the latest version.
  • Once done, restart the system to apply changes.

Manual Update:

If you can’t find any pending updates, visit the official website of the respective manufacturer for the graphics card that you’re using. Make sure to search for the graphics card model on the website and download the latest version of the graphics driver. Then run the installer and complete the driver installation process. You can jump to the link below to do so:

10. Try Changing the In-Game Language

This specific workaround might help in fixing the dev error 6015 up to some extent because multiple players have done it. Make sure to change the in-game language of COD MWIII via Steam. To do so:

  • Open Steam > Go to Library.
  • Right-click on the COD Modern Warfare 3 game.
  • Select Properties > Select the Language tab.
  • Now, change the language to your preferred one.
  • Finally, launch the game & check for the issue again.

11. Reinstall COD Modern Warfare 3

If none of the workarounds come in handy then make sure to uninstall and reinstall the COD Modern Warfare III (2023) game on your gaming device. Sometimes issues with the game installation directory may cause multiple conflicts. You should uninstall and reinstall the game by following the steps below.

For Steam:

  • Open the Steam client on your PC.
  • Go to Library > Right-click on COD MWIII.
  • Select Uninstall > Click on Delete to confirm.
  • Wait for the uninstallation process to complete.
  • Exit the Steam client > Open File Explorer.
  • Copy & paste C:\Program Files (x86)\Steam\steamapps\common on the address bar.
  • Press Enter to search for the location.
  • Go to the COD MW3 folder > Delete the folder completely.
  • Reboot the PC to apply changes.
  • Finally, open Steam > Reinstall the COD MWIII game again.


  • Open the client.
  • Select Call of Duty: Modern Warfare III from the left panel.
  • Choose the Options menu on the left side.
  • Click on Uninstall Game > If prompted, confirm the uninstallation process.
  • Once done, close, and reboot the PC.
  • Next, open > Reinstall COD: MWIII.
  • Wait for the game to be completed.
  • Finally, launch the game to check for the issue.

For PlayStation:

  • Head over to the PlayStation Home Screen.
  • Go to the Game Library.
  • Highlight the Call of Duty: Modern Warfare 3.
  • Press the Options button on the controller.
  • Now, select Delete > Confirm to uninstall it.
  • Download the MWIII game from the Game Library or via the PlayStation Store.
  • Finally, reinstall the game to check for the issue.

For Xbox:

  • Press the Xbox button on the controller.
  • Go to My games & apps.
  • Select Games > Highlight Call of Duty: Modern Warfare 3.
  • Press the Menu option > Select Uninstall.
  • Confirm to uninstall it.
  • Once done, go to ‘My games & apps’.
  • Navigate to Ready to Install or the Xbox Store to reinstall the MWIII game.

12. Contact Activision Support

Last but not least, you should contact Activision Support for the Call of Duty Modern Warfare III (2023) game to get better assistance. Additionally, you can try submitting the support ticket so that the developers can deeply investigate the issue & help you further.

That’s it, guys. We assume this guide was helpful to you. For additional queries, you can comment below.

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