Plesk update fails: Conflicting values set for option Signed-By regarding source

Symptoms

• A Plesk update attempt executed on Debian-based operating system fails with errors that are similar to the following:

  CONFIG_TEXT: Synchronizing the Debian APT package index files...
  E: Conflicting values set for option signed-By regarding source https://autoinstall.plesk.com/PMM_1.1.0/ jammy: /etc/apt/keyrings/plesk-ext-panel-migrator.gpg !- /etc/apt/keyrings/plesk-ext-site-import.gpg
  E: The list of sources could not be read.
  Warning: there are errors in 'apt-get update'

Cause

The repository https://autoinstall.plesk.com/PMM_1.1.0/ jammy is listed multiple times in your sources configuration for the package manager, but each entry points to a different GPG key file, more specifically /etc/apt/keyrings/plesk-ext-panel-migrator.gpg and /etc/apt/keyrings/plesk-ext-site-import.gpg.

The extensions Plesk Migrator and Site Import use two separate GPG keys in one keying file nowadays, however on your server two separate keyring files still exist and this causes a conflict.

As a consequence, since APT does not allow two different signed-By values for the same repository URL and distribution, it fails to read the sources list.

Resolution

In order to resolve the issue, you must do the following:

1. Log into Plesk

2. Finish any unfinished migrations and transfers via the Plesk Migrator and Site Import extensions

3. Remove the Plesk Migrator and Site Import extensions from Plesk by using the steps in this article:

How to manage Plesk extensions (install, disable, remove, update) - section Removing a Plesk extension

4. Update Plesk Obsidian to the latest build by using the steps in this article:

How to update Plesk Obsidian to the latest build

5. After the update succeeds, install the Plesk Migrator and Site Import extensions again by using the steps in this article:

How to manage Plesk extensions (install, disable, remove, update) - section Installing a Plesk extension