Welcome to Algorand!
I’ve tested on a fresh Ubuntu 21.04 installation in Docker (docker run -it ubuntu:21.04 bash) and it worked following the steps in Install a node - Algorand Developer Portal (removing sudo because the Docker distribution runs in root).
Have you followed strictly the steps in Install a node - Algorand Developer Portal without encountering errors?
I see two potential explanations if the above is true:
- The package got corrupted (this may also happen if you don’t have enough space on your disk (
df -hshows the space left - you must always have a few GB left otherwise weird things can happen). - Something in your configuration is causing an issue. Are you using an unusual shell? Can you try to debug following ubuntu - dpkg: new pre-installation script returned error exit status 1 - Unix & Linux Stack Exchange ?