CasaOS containers borked on Proxmox LXC
Date:
[2nd Dec 2025]
Something borked CasaOS inside LXC in Proxmox.
Either docker or containerd.io is leading to a bunch of errors inside CasaOS and need to be downgraded while a fix is not made available.
apt update
apt-cache policy docker-ce
apt-cache policy containerd.io
This lists the versions available for docker-ce and containerd.io. The ones that worked for me since I'm still using Debian bookworm were docker-ce=5:28.5.2-1~debian.12~bookworm and containerd.io=1.7.28-1~debian.12~bookworm.
systemctl stop docker.socket
systemctl stop docker
apt remove -y docker-ce docker-ce-cli containerd.io don't use purge here since you'll lose containers and configuration files.
apt install -y docker-ce=5:28.5.2-1~debian.12~bookworm docker-ce-cli=5:28.5.2-1~debian.12~bookworm containerd.io=1.7.28-1~debian.12~bookworm
systemctl start docker
sudo apt-mark hold docker-ce docker-ce-cli containerd.io to pin the packages so a future update won't bork them again.
Done.
EDIT : New method that doesn't need to withhold packages from being upgraded courtesy of linkylink
TLDR
You can fix it without downgrading Docker or Portainer. You can add the variable DOCKER_MIN_API_VERSION=1.24 to the docker service config ( this fixes the issue for Traefik aswell if you are using this, since traefik uses the version 1.24 )
systemctl edit docker.service
Add this part above the line ### Lines below this comment will be discarded:
[Service]
Environment=DOCKER_MIN_API_VERSION=1.24
Save the file and exit
systemctl restart docker
Worked like a charm.