Warzone 2.0 'Dev Error 657' Explained (And How To Fix It)
It seems the current flagship installments of the "Call of Duty" franchise are having about as many issues as they have features. "Warzone 2.0" and "Modern Warfare 2" players have been plagued with issues of various kinds since the games' launches, ranging from fairly straightforward hiccups like "voice service unavailable" or "unable to access online services" to increasingly bizarre and obscure errors like Puget Atlus, Hueneme Concord, and the dreaded legion of dev error numbers.
So it's no surprise that players are struggling with yet another issue – this time, in the form of dev error 657. Thankfully, unlike some of the other errors (such as the massive and unpredictable headache that is dev error 6039), this one has a concrete cause that arises from missing or corrupted game files. The bad news is, knowing the exact nature of the issue doesn't necessarily make it any easier or simpler to fix than any of the other myriad of "Call of Duty" errors — here's a step-by-step guide on troubleshooting both short-term and chronic cases of dev error 657 in "Call of duty: Warzone 2.0."
Keep some preventative measures in mind before you start
While Dev Error 657 might sound like an easy enough issue to fix, some users have reported chronic cases that arise after varying lengths of gameplay sessions. Since you probably don't want to see the error pop right back up after you've just finished resolving it, let's review a few preventative measures to implement before diving into the nitty gritty troubleshooting. Because Dev Error 657 is an issue with file integrity, it's important to make sure that files don't get corrupted or otherwise obstructed during downloading or updating procedures — the first thing to do is to make sure that the game is whitelisted on both your antivirus and firewall, checking that your internet connection is stable, and that you have a good connection to the game's servers. It also wouldn't help to try clearing out your temporary network connection files using methods outlined in our guide for resolving the Hueneme Concord error, just to ensure nothing gets corrupted during downloading.
Finally, PC players should ensure that "Warzone 2.0" is being manually forced to run on Direct X 11, just to make sure nothing gets scrambled during play sessions. It's as simple as opening up the game's configuration (under "Properties > General > Launch Options" in Steam and "Game Settings" in the Battle.net launcher) and adding "–d3d11" to the additional commands line.
Quick fixes for Dev Error 657
For starters, you should be going through the very basic steps of troubleshooting — restarting your game, then your computer and router (while waiting at least 30 seconds in between shutdown and restart for proper power cycling), then checking for updates on your game and platform system (as well as graphics and network drivers for PC players).
If none of those worked, the next thing to do would be to verify and repair any broken game files. PC players can find the option to "verify integrity of game files" under "Properties > Local Files" in Steam, while Battle.net users can find "Scan and Repair" in the main drop-down for the game's configuration. Xbox users can download the Xbox app, login, and click "Verify and Repair" under "Manage > Files."
Unfortunately for PlayStation users, there isn't really a way to scan for broken files beyond doing a clean uninstall, cache clear, and fresh installation, but there is a quick fix you can try before settling in to re-download the massive game. Dev Error 657 on consoles can sometimes be caused by out-of-date, broken, or invalid console licenses — head into the settings menu, navigate through "Users > Accounts > Other," then click "Restore Licenses." After the process finishes, restart your system and try again to see if the error persists.
You may have to sit down for a full reinstalling session
Unfortunately, if none of the quicker fixes work, the only thing left to do is purge the entirety of your game files and reinstall them on a completely clean slate. Again, because of the size of the game, this can be quite a pain in the neck — especially because you'll need to take the time to check for any leftover files before even sitting down to redownload.
First, uninstall the game. Then, clear your cache — you can find a rundown of all the correct steps for fully flushing any and all game files for every platform on SVG's guide to Dev Error 6039.
An important step to take before going ahead with reinstallation is to implement the preventative measures outlined previously, if you haven't already. Even if you have, it won't hurt to double check in case any of the settings have reverted (Windows system updates are notorious for messing up any manually configured settings at random). PC users should also go through any relevant folders outside of the main Steam directory to ensure that there aren't any leftover folders in places like My Documents, My Games, or even more obscure file paths like "C: > Users > [Username] > Appdata," and all three folders underneath.
Once you're sure all files have been purged, all internet connections are stable, all relevant processes are whitelisted, and all the relevant systems have been updated, go ahead and reinstall the game.