Proxmox 'Guest Agent Is Not Running': Every Cause and How to Fix Each One

This is one of the most confusing Proxmox errors, because it usually shows up after you’ve already done the “obvious” fix — installed the guest agent, confirmed it’s running inside the VM, and it still says not running on the Proxmox side. The reason is that “guest agent not running” can mean five or six genuinely different things, and the error message doesn’t tell you which one you’re dealing with. ...

August 14, 2026 · 4 min · 732 words · Vosik

Proxmox Wake-on-LAN Not Working? You're Probably Solving Two Different Problems

Almost every Proxmox WoL thread is actually two unrelated conversations happening at once, because “wake-on-lan on Proxmox” means one of two very different things depending on what you’re trying to wake up: Waking the physical Proxmox host from a full shutdown — this is regular hardware WoL, and it works, with some Proxmox-specific gotchas. Waking a VM that’s powered off — this is a different problem entirely, and traditional magic-packet WoL fundamentally doesn’t work for it, because a VM’s network card isn’t a physical device that can sit in a low-power state. If you’ve been mixing solutions from both categories and nothing works, that’s why. Let’s do them separately. ...

August 14, 2026 · 4 min · 842 words · Vosik

Proxmox 'No Valid Subscription': Why It Happens and How to Fix It (PVE 8 & 9)

If you just installed Proxmox VE and you’re seeing a “No valid subscription” popup every time you log into the web UI — or apt update is failing with a 401 error — don’t panic. Nothing is broken. This is expected behavior on a fresh install without a paid subscription, and it’s a two-minute fix. There are actually two separate issues hiding under one confusing message, and most guides mix them together. Let’s untangle them. ...

August 13, 2026 · 4 min · 761 words · Vosik