Comment 6 for bug 1954635

We encountered this on a server build on 22.04, though admittedly a daily image before the final was created.

While we didn't save the log, we encountered the same sort of behavior you did. Going off of Michael's comment and reading the logs, it looks like Todd was using Ventoy, which we were also using as well as complicated networking and partitioning.

For reference, Ventoy is software to run bootable iso files from a drive rather than needing to directly writing them to said drive.

When we did the installation with the final iso directly written to a flash drive, and did the same installation procedure, everything worked perfectly.

I think this error is due to something Ventoy is doing that the installer doesn't like. Whether or not that is something that is considered Ubuntu's fault, I'm not sure.