That's weird really, can you reproduce it consistently, or was it a one-off?

If you can reproduce, please change your mirror to http://kali.download/kali in /etc/apt/sources.list. Then sudo apt distclean && sudo apt update. Can you still reproduce it?

If so, can you please paste the output of:

curl -sI http://kali.download/kali/dists/kali-rolling/main/Contents-amd64.gz

I'm trying to assess if you hit some Cloudflare caching issue.

I just restored from a backup.

Ok, it's happening off and on.

If it doesn't work, I can try sudo apt update a couple of times, and it works.

I think it's pulling from another ip address.

I'm guessing one of the ip addresses is offline now. (54.39.128.230 80)

Here's the output when I encounter an error.

curl -sI http://kali.download/kali/dists/kali-rolling/main/Contents-amd64.gz
HTTP/1.1 200 OK
Date: Wed, 29 Oct 2025 08:48:08 GMT
Content-Type: application/gzip
Content-Length: 52315180
Connection: keep-alive
CF-RAY: 996169847f2b1d8b-BOS
Last-Modified: Thu, 23 Oct 2025 18:04:47 GMT
ETag: "68fa6e3f-31e442c"
Expires: Sun, 02 Nov 2025 18:12:24 GMT
Cache-Control: max-age=864000
CF-Cache-Status: HIT
Age: 484336
Accept-Ranges: bytes
Server: cloudflare

ping

I'm guessing one of the ip addresses is offline now. (54.39.128.230 80)

Well this is the IP of http.kali.org, it's the redirector, all users hit this machine by default and then their request get redirected to a mirror close-by. I can tell you for sure that it's not offline, and it's never offline. If it returns a 404, it's because you request a file that doesn't exist.

Here's the output when I encounter an error.

[...] http://kali.download/kali/dists/kali-rolling/main/Contents-amd64.gz
HTTP/1.1 200 OK

But that's a "200 OK", so the file exists.

If I go back to your initial report, this line doesn't look right:

Error: Failed to fetch http://http.kali.org/kali/dists/kali-rolling/main/Contents-amd64 404 Not Found [IP: 54.39.128.230 80]

I mean, the file is Contents-amd64.gz and not Contents-amd64. I don't know why apt would request the wrong file, that doesn't make any sense....

I just restored from a backup.

Don't tell me that you resurrected a Kali install that is many years old ?

No, my backup is dated 10/03/25.

I'm using Win11 as a host machine, with VmWare Workstation 17 Pro, with Kali as a virtual machine.

Everything is patched, and up to date.