How To Fix “Dev Error 6634 Xbox Series X”

The PC, PS5, and Xbox One Series X and S frequently experience the development error 6634. Whether you’re having trouble playing because of a corrupted PC cache or a failed Multiplayer Pack installation, Call of Duty: Modern Warfare is to blame.

The next-generation gaming experience on the Xbox Series X has been largely smooth for many enthusiasts. However, like any other platform, it isn’t free from errors.

One such hiccup players have encountered is the notorious “Dev Error 6634.” If you’re grappling with this issue or seeking insights into Xbox’s dev mode and errors, this article is your resource.

What is Dev Error 6634 Xbox Series X?

The “Dev Error 6634” is a development-related error that users have reported while playing certain games, most notably during sessions of “Call of Duty.” This error results in unexpected crashes, often abruptly ending gameplay and causing frustration among players.

Causes of Dev Error 6634 Xbox Series X Error:

While the exact root of this error remains somewhat elusive, several triggers have been identified:

  • Game Files Corruption: Corrupted game files can interfere with smooth gameplay, leading to the error.
  • Software Incompatibilities: Sometimes, game updates or Xbox firmware might not be in sync, resulting in conflicts.
  • Backend Server Issues: On occasion, the issue might not be on the user’s end at all. Game server issues can sometimes manifest as such errors.

How To Fix Dev Error 6634 Xbox Series X

Watch glitched items – It seems that

When combining the Stitch operator with any Cold War watch, the player frequently experiences fatal game crashes due to a bug. Even as I write this, there is still no fix for the problem. Unequipping the watch item will resolve the incompatibility that is triggering the error message.

Dev Error 6634 Xbox Series X

The problem is due to either Multiplayer Pack 2 or Multiplayer Pack 3.

If you’re having this problem on a console (Xbox Series X/S or Playstation 5), it’s probably because of a bug in the partial install feature. Reinstalling Multiplayer Pack 2 and Multiplayer Pack 3 should fix the problem.

Method 1: Remove it From Your Watch Equipment

It turns out that a watch + operator combination that causes the game to crash during specific on-map actions is one of the most common causes of the Dev code 6634 in Call of Duty: Modern Warfare.

Some players have reported this issue while attempting to utilise the Stitch operator with ANY Cold War watch. If this is your situation and you have a watch equipped in your loadout for Call of Duty: Modern Warfare, try removing it as instructed below to see if it helps.

Step 1: Turn on Call of Duty: Modern Warfare and head to the main menu.

Step 2: Then, go to the top Ribbon menu and choose Weapons.

Step 3: You may reach the Watch Select sub-menu after you’re inside the Weapons menu.

Step 4: Before saving your modifications, you should make sure the corresponding toggle in the Watch Select menu is set to None.

Step 5: Once the watch has been unequipped, any operation you choose should no longer result in the same conflict that was previously producing the problem code.

Method 2: Clearing Out The Cache On Battle.Net (PC Only)

On PC, a corrupted cache is likely to blame for the occurrence of Dev Error 6634 when starting the game through Blizzard’s launcher (Battle.Net). Multiple players have confirmed that we are unable to connect to or keep up a consistent multiplayer session.

Those who have had this problem say it can be permanently resolved by deleting all files in the Blizzard Entertainment folder (which houses the cache folder) and restarting the computer.

If you’re seeing Dev Error 6634, you can fix it by deleting the cache, as detailed below.

Step 1: To begin, please ensure that and any games opened through it are closed.

Step 2: To bring up the Run dialogue box on Windows, use the Windows key plus R. The ProgramData folder can be accessed by typing “%ProgramData%” and hitting the Enter key.

Step 3: Enter ProgramData, open the Blizzard Entertainment folder, and then go to > Cache.

Step 4: Select everything in the Cache folder by pressing Ctrl + A (or by selecting everything with the mouse), then right-click on a chosen item and select Delete from the context menu that appears.

Step 5: Once the cache folder has been emptied entirely, you should restart the computer and then launch Call of Duty again.

How Do I Get Rid of Dev Error on Xbox?

Addressing the Dev Error 6634 involves a series of troubleshooting steps:

  1. Restart the Game and Console: Begin with the basics. Often, a simple restart can clear temporary glitches.
  2. Check for Game and Console Updates: Ensure both your game and Xbox Series X firmware are updated to the latest versions.
  3. Reinstall the Game: If the error persists, consider uninstalling and then reinstalling the game. This can rectify corrupted game files.
  4. Clear Xbox Cache: Clearing the Xbox’s cache can solve a plethora of issues. To do this, turn off the console, unplug it, wait for about 10 minutes, plug it back in, and turn it on.
  5. Check Game Servers: If the error is prevalent among many users simultaneously, it might be worth checking the game’s official channels or forums for server-related announcements.

How Much is Dev Mode on Xbox?

“Dev Mode,” or Developer Mode, allows users to develop and test games and apps for Xbox. To activate the Xbox Dev Mode, one has to pay a one-time fee, which, as of the last update, is $19. This gives you access to the Microsoft Developer Program and allows you to run, test, and develop your own content on Xbox.

Why Do I Always Get Dev Error?

If you’re repeatedly getting Dev Errors:

  • Persistent Game Issue: The game might have unresolved bugs. Checking game forums or the developer’s site can provide insights.
  • Hardware Issues: Rarely, repeated errors can be a sign of underlying hardware problems, especially if the error isn’t limited to one game.
  • Incompatible Modifications: If you’ve made modifications to the game or system, it might be causing the errors.


The Dev Error 6634 on Xbox Series X, while frustrating, often has straightforward solutions. The key lies in methodical troubleshooting. Regular system and game updates, combined with being part of the game’s community, can provide early warnings and solutions to such issues.

After all, a smooth gaming experience is what every enthusiast aims for, and knowledge is a crucial tool in ensuring just that.