How To Fix Dev Error 6635 On Xbox | Updated 2023

The Dev Error 6635 on Xbox is a common error that pops up while playing Call of Duty games on Xbox consoles. This error prevents you from properly launching or playing the game. In this article, we will go over the main reasons behind this error code and provide solutions to fix it. The focus is on allowing Xbox players to enjoy Call of Duty games again after being blocked by Dev Error 6635.

What Causes Dev Error 6635 On Xbox?

Here are some of the most common reasons why Dev Error 6635 shows up on Xbox consoles:

Corrupted Game Files

The game files related to Call of Duty on your Xbox may have been corrupted or damaged somehow. This prevents the game from launching correctly.

Xbox Overheating

If your Xbox console is overheating, it can cause various errors like Dev Error 6635 to appear. Overheating can happen due to dust build-up or placing the Xbox in enclosed spaces.

Outdated/Missing Game Updates

Call of Duty games need regular updates to fix bugs and add new content. If your game needs to be updated or include crucial updates, Dev Error 6635 may appear.

Conflicts with Xbox Settings/Software

Incorrect or conflicting settings/software on your Xbox can also trigger Dev Error 6635. This includes things like incorrect language settings.

Hardware Failure

In rare cases, a hardware failure like a faulty hard drive can also cause Dev Error 6635 to occur while playing Call of Duty games.

Solutions To Fix Dev Error 6635 On Xbox

Below are the top solutions to successfully fix Dev Error 6635 on your Xbox console.

Solution 1: Clear the Xbox Console Cache

Clearing the cache removes temporary files and frees up system resources—the Xbox cache stores temporary system files and data to optimize performance. Over time, this cache can get overloaded or corrupted, causing errors like Dev Error 6635. Clearing it erases these temporary files, frees up space, and clears any corrupted data from the cache. This can fix many errors without reinstalling or losing game progress. To clear the cache on Xbox, follow these steps:

  1. Go to the Xbox dashboard and press the Xbox button to open the guide panel.
  2. Select Settings > Devices & connections > Blu-ray.
  3. Select Persistent storage > Clear persistent storage.
  4. Restart your Xbox console for changes to take effect.

Solution 2: Perform a Hard Reset 

A hard reset (power cycle) completely reboots your Xbox and refreshes its memory. It clears any corrupted data from RAM, shuts down background processes, and restarts them. This can fix software bugs, memory leaks, and other issues that cause errors, like Dev Error 6635. It is an effective troubleshooting step before reinstalling the game. Follow these steps to reset your Xbox hard:

  1. Press and hold the Xbox power button on the console for 10 seconds. 
  2. Wait for the console to power down fully.
  3. Wait for 30 seconds before unplugging the power cord. 
  4. Reconnect the power cord and turn your Xbox back on.

Solution 3: Reinstall the Call of Duty Game

Reinstalling the Call of Duty game, you are trying to play essentially replaces all of its core files with a fresh copy. This ensures any corrupted, out-of-date, or missing files are fixed. It eliminates potential conflicts or bugs in your current install, causing Dev Error 6635. Reinstalling is highly effective, but you may lose unsaved progress. Follow these steps: 

  1. Go to My games & apps > See all > Call of Duty: Modern Warfare.
  2. Press the Menu button on the game tile and select Uninstall All.
  3. Go to the Microsoft Store and redownload the Call of Duty game.
  4. Let the game fully install and apply the latest updates.

Solution 4: Adjust Xbox Graphics Settings

Incorrect graphics settings can affect game performance. Call of Duty games are graphics intensive. Using the wrong resolution, frame rates, or other GPU settings on your Xbox can sometimes lead to conflicts and cause errors like Dev Error 6635. Adjusting the graphics settings to recommended defaults can help resolve this. Follow these troubleshooting tips:

  1. Go to Settings > General > TV & display options.
  2. Set Resolution to 1080p or 720p for best results.
  3. Disable Allow 4K, Allow HDR, and Allow variable refresh rate. 
  4. Set the Color depth to 8-bit. Disable 10-bit and 12-bit.
  5. Disable ALLM and VRR if enabled. Set the Refresh rate to 60Hz.
  6. Launch Call of Duty and check if Dev Error 6635 is now fixed.

Final Thoughts

Following the solutions in this article, like verifying game files, clearing cache, reinstalling the game, and adjusting graphics settings, can help successfully fix Dev Error 6635 on Xbox. Reach out to Activision support if the error persists after trying these fixes. The key is to be patient and systematically isolate the cause with proper troubleshooting.


I get Dev Error 6635 when loading multiplayer maps in Call of Duty. How can I fix this?

This specific error points to an issue with the game’s multiplayer portion. Try fully reinstalling just the multiplayer pack from the Manage Game menu. This will refresh the corrupt multiplayer files causing crashes on certain maps.

Does clearing my Xbox profile cache help resolve Dev Error 6635?

Yes, clearing the profile cache could fix Dev Error 6635. Go to Settings > General > Personalization > My profile > Clear profile cache. Restart your console afterward. This clears corrupted data linked specifically to your profile.

What Xbox system settings could be causing Dev Error 6635?

Check your Xbox display settings under Settings > General > TV & display options. Incorrect resolution, HDR, variable refresh rate, or color depth settings can conflict with Call of Duty and cause Dev Error 6635.

How can I troubleshoot my Xbox storage to fix Dev Error 6635?

They transfer or reinstall Call of Duty to a different external or internal drive. Corrupted sectors on your current drive may be causing dev error 6635. Run a full scan & repair as well on the current drive.

Will a factory reset fix Dev Error 6635 on my Xbox?

A full factory reset will return your Xbox to default settings and remove all games & data. This guarantees any software bugs causing Dev Error 6635 are removed. Try less drastic steps first, though, as you’ll have to reinstall and set up everything again.

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