Fix the “Proxmox apt-get update failed exit code 100” error by switching from the enterprise to the free repository using easy or manual steps. Our Proxmox support team is always here to help you.

How to Fix: Proxmox apt-get update failed exit code 100

When managing a Proxmox Virtual Environment (PVE), you might encounter the dreaded error: Proxmox apt-get update failed exit code 100. This issue generally appears either while using the web GUI or when running apt-get update via terminal on a freshly installed Proxmox node.

So what does it mean?

This error typically signals a problem with the APT package system, most commonly, a misconfiguration in the repository settings or an authentication issue.

Understanding the Cause

When you see the error:

Err:7 https://enterprise.proxmox.com/debian/pve buster InRelease

401 Unauthorized [IP: x.x.x.x 443]

E: Failed to fetch https://enterprise.proxmox.com/debian/pve/dists/buster/InRelease 401 Unauthorized [IP: x.x.x.x 443]

E: The repository ‘https://enterprise.proxmox.com/debian/pve buster InRelease’ is not signed.

TASK ERROR: command ‘apt-get update’ failed: exit code 100

…it means your Proxmox instance is trying to reach the Enterprise Repository, which is only accessible to users with a valid subscription. If you’re using the free edition of Proxmox without a subscription, the error is inevitable, unless you switch to the non-subscription (free) repository.

The Fix

Thankfully, Proxmox offers a free repository, but it’s not enabled by default. Here’s how you can solve this in just a few steps.

Preparation

Use the Proxmox web GUI by navigating to >_ Shell, or use an SSH client to connect to your Proxmox server.

Easy Method

If you want a quick and effective fix:

cp /etc/apt/sources.list.d/pve-enterprise.list /etc/apt/sources.list.d/pve-enterprise.list.backup && echo -e "#$(cat /etc/apt/sources.list.d/pve-enterprise.list)" > /etc/apt/sources.list.d/pve-enterprise.list

This command backs up the pve-enterprise.list file and comments out the enterprise repository line.

After that, try updating again using:

apt-get update

This should bypass the issue.

Manual Method

Prefer doing things manually? Follow these steps:

3.1 Change Directory

cd /etc/apt/sources.list.d

3.2 Backup the File

cp pve-enterprise.list pve-enterprise.list.backup

3.3 Edit the File

nano pve-enterprise.list

3.4 Comment Out the Enterprise Repo

Add a # at the beginning of the line:

#deb https://enterprise.proxmox.com/debian/pve buster pve-enterprise

3.5 Update

Run:

apt-get update

This should now complete without throwing the error. You might also encounter container lock issues during updates, such as this Proxmox CT locked snapshot delete error.

[If needed, Our team is available 24/7 for additional assistance.]

Conclusion

If you’re seeing this issue, it’s most likely due to the default enterprise repository being inaccessible without a subscription. You can quickly fix this by disabling that repository and switching to the free one, either via a one-liner or manually. This simple change allows your system to update correctly and keeps your Proxmox setup running smoothly.