Failed to install add-on dev: 500 Server Error

[AlexUPGR]

Problem/Motivation

Can't install

(Why the issue was filed)
Failed to install add-on
Can't install ghcr.io/lbouriez/addon-plex/amd64:dev: 500 Server Error for http+docker://localhost/v1.41/images/create?tag=dev&fromImage=ghcr.io%2Flbouriez%2Faddon-plex%2Famd64&platform=linux%2Famd64: Internal Server Error ("manifest unknown")

Expected behavior

Failed to install add-on

(What you expected to happen)

Actual behavior

(What actually happened)

Steps to reproduce

(How can someone else make/see it happen)

Proposed changes

(If you have a proposed change, workaround or fix,
describe the rationale behind it)