How To Fix Apt-Get Update Error 404 Not Found Ubuntu 24.0...

Issue	Likely Cause	Quick Fix
404 Not Found	Deprecated PPA or Repository	Remove the broken PPA from sources.list
404 Not Found	Server Mirror Offline	Change the Ubuntu mirror to Main Server
404 Not Found	Release Name Mismatch	Verify “noble” in sources.list.d

Table of Contents

What is apt-get update error 404 not found Ubuntu 24.04?

The “apt-get update error 404 not found” in Ubuntu 24.04 (Noble Numbat) occurs when the APT package manager cannot locate a specific repository file on the remote server. This usually happens because a PPA does not yet support the 24.04 release or a repository has been moved.

When you run the update command, Ubuntu scans your sources list. If a URL returns a 404 status, it means the directory for “noble” packages is missing on that server. This stops your system from updating its package cache correctly.

Step-by-Step Solutions

Step 1: Identify the Broken Repository

First, you need to find exactly which repository is failing. Run the update command in your terminal:

sudo apt-get update

Look for the lines starting with “W:” (Warning) or “E:” (Error) that contain “404 Not Found”. Note the URL and the name of the repository causing the issue.

Step 2: Remove the Problematic PPA

Most 404 errors on Ubuntu 24.04 are caused by older PPAs that haven’t been updated for the Noble Numbat release. You can remove these using the following command:

sudo add-apt-repository --remove ppa:repository-name/ppa

Replace “ppa:repository-name/ppa” with the actual name identified in Step 1. This cleans up your sources list and allows the update process to proceed.

Step 3: Switch to the Main Archive Mirror

If the error points to the official Ubuntu mirrors, your local regional server might be out of sync. Switching to the Main Server often fixes this.

Open “Software & Updates” from your application menu. Under the “Ubuntu Software” tab, find “Download from:” and select “Main Server”. Close and click “Reload” when prompted.

Step 4: Clean the APT Cache

Sometimes stale metadata causes 404 errors even after you have fixed the sources. Clear the local cache to force a fresh download:

sudo rm -rf /var/lib/apt/lists/*
sudo apt-get update

This command removes the old list files. The next update will pull entirely new data from the servers, ensuring no old 404 links remain in your local cache.

Step 5: Check for Typos in Manual Sources

If you manually added a repository to /etc/apt/sources.list, check for typos. Ensure the distribution name is correctly set to noble.

cat /etc/apt/sources.list

Ensure every line pointing to an external repo matches the Ubuntu 24.04 codename. If you see “jammy” or “focal” on a 24.04 system, it may trigger a 404 if the vendor doesn’t provide cross-version support.