How to fix the Detrick Guernsey error in Modern Warfare 2 and Warzone 2

Another oddly named error code strikes again.

Image via Activision

Call of Duty has some odd error code names, and the Detrick Guernsey error code has recently been one of the more prevalent and annoying ones.

In game development, error codes are given unique names to help differentiate them from others and give developers more insight into why they may be happening. In Modern Warfare 2 and Warzone 2, these error codes sometimes have the names of actual human beings, like Travis Rilea or Detrick Guernsey.

Here’s what the Detrick Guernsey error will look like in-game when it pops up:

  • Connection Failed
    • Login Servers are currently undergoing maintenance. [Reason: DETRICK GUERNSEY]

If you’re here, you probably already knew that, because “Reason: DETRICK GUERNSEY” makes zero sense and likely has caused some confusion and a whole lot of frustration when you’re just trying to wind down with some matches in MW2 or Warzone 2.

Related: Stuck searching for a match in Warzone 2, DMZ, or MW2? Here’s what to do

Here’s all you need to know about Detrick Guernsey in CoD.

How do I fix the ‘Detrick Guernsey’ error in MW2 and Warzone 2?

Call of Duty operators running into action in a MW2 multiplayer match.
Image via Activision

The error is rather self-explanatory thanks to the message that accompanies it. It’s a common error that pops up whenever players are attempting to access the servers when they’ve been taken down for maintenance.

CoD servers going down for maintenance are a rare occurrence, but it does happen on occasion. For example, they were taken down for a two-hour period in the very early morning hours of May 3, 2023, and many players saw the message then.

To check and see if the CoD servers are having an outage or are down for official maintenance, first check out the Activision online services page to see if MW2 and Warzone 2 are currently experiencing any issues.

Screengrab via Activision

If you’re getting the Detrick Guernsey error, the most likely scenario is that there’s nothing you can do to fix it on your end. It’s probably server maintenance. If there’s no maintenance and you’re still getting the code, however, then it’s probably unscheduled and sudden server problems across CoD’s multiple titles.

Related: How to fix the Travis-Rilea error in Modern Warfare 2 and Warzone 2

Server maintenance, while rare, is sometimes a necessity to help fix ongoing issues with the game, such as extended periods of lag or game server instability. Be patient, maybe hop on another game for a little while, and the Detrick Guernsey error should subside in due time and you will be able to drop in for CoD games eventually.


Scott Duwe
Staff Writer & Call of Duty lead. Professional writer for over 10 years. Lover of Destiny 2, Metal Gear, Pokémon, Resident Evil, Final Fantasy, Marvel Snap, and more. Previous bylines include PC Gamer, Red Bull Esports, Fanbyte, and Esports Nation. DogDad to Yogi the Corgi, sports fan (NY Yankees, NY Jets, NY Rangers, NY Knicks), Paramore fanatic, cardio enthusiast.

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