Dev error 6456 is yet another one in the long line of dev errors that CoD Modern Warfare and Warzone have seen. All the previous dev errors we’ve covered have involved some crazy fixes like switching Activision accounts or downloading the entire game again. Dev Error 6456 is much simpler to resolve.
How to fix dev error 6456 in CoD Modern Warfare/Warzone
According to the various thread posts we’ve gone through, it seems that Call of Duty Modern Warfare & Warzone have issues with third-party softwares. These can be any softwares which have overlays and they tend to interfere with the game.
Some users have also reported that whenever these third-party softwares try to display a notification, the game crashes and presents dev error 6456.
Discord and NZXT seem to be the most popular causes of this error and we recommend closing them before playing the game.
Turn off overlay for Discord
Turn off Discord’s overlay with the following steps.
Open your User Settings from this icon.

A new window will open and there will be a large menu on the left. Scroll down and you will see a submenu called Game Settings. In that menu, choose Overlay and a new window will open. Turn off the Enable in-game overlay setting with this button.

Shut overlay for NZXT cam
Open NZXT cam app’s settings and do the following.
Go to Settings within CAM, click on FPS tab and then click on the Enable CAM overlay slider and it should move to the left of the screen. Click apply and the overlay should go away.
If you have any other apps installed with overlay features like Nvidia GeForce, try disabling all of them for maximum effect.
Outdated GPU drivers
Many people have reported that dev error 6456 shows up with a DirectX error. This has led some people to believe that maybe outdated GPU drivers are the ones causing it.
If you’ve disabled all overlays in the above step but still face this error, you can try updating your GPU drivers.
If you have an Nvidia GPU, use this guide to update your drivers. In the case you use an AMD GPU, look at this guide.
DirectX version
Done everything mentioned above but still facing the error? Check if your DirectX has the latest version installed. If you’re running an old version, update it and see if it makes a difference. If you have the latest version, try reinstalling it.
Both these steps can be accomplished by looking at the official guide from Microsoft.
If this guide helped you out, do give us a share! In case you still need help, leave a comment down below or reach us on Twitter @awsmtips.
More Dev errors
There are a lot of Dev errors going on around right now and we’ve covered a few of them. You can read them here:

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