How to fix the "our level fastfile is different from the server" error - Call of Duty: Black Ops 6

Would it really be a major game launch without some errors? Black Ops 6 is bringing back a classic.

Activision
1

Saying an error code is a classic might be a bit much, but being told that "our level fastfile is different from the server" is something that I think a lot of Call of Duty players will be used to, and the issue has returned in Black Ops 6.

How to fix the "our level fastfile is different from the server" error - Call of Duty: Black Ops 6

Black Ops 2 crew looking for loot in Zombies mode

Source: Activision

Thankfully, the fix for this is easy; you simply need to restart your game. Yes, it is a little bit annoying, but not the end of the world. A quick restart will have everything back in order, and you can dive into the campaign, multiplayer, or zombies mode in Black Ops 6.

For those who might be curious about what a fastfile is, my understanding is that it can be anything. The actual contents and function of a fastfile can vary from engine to engine and game to game, but it will be some kind of archived information that the game needs to run. What is likely to happen is that some files are not overwritten during an update or package send, and that's the cause of the issue.

Restarting the game then just reloads all data and solves the issue. Unless the loaded game files and the server build files are perfectly matching, you cannot make a live connection to the game, hence the error message. At least that is what I have deduced from looking into these odd little files.

For more helpful guides, be sure to check out our Black Ops 6 page.

Contributing Guides Editor

Hailing from Ireland, Aidan has been conditioned by local weather conditions to survive hours at his PC grinding through whatever game is offering the lowest possible drop rates for loot. He thinks the easiest way to figure out what fans of games want to read is to just be a fan of games. You can normally find him logged into Warframe, Destiny, or a gacha game. You can reach out to him on X @scannerbarkly.

Hello, Meet Lola