magento/composer-root-update-plugin is locked to version 1.0.0 and an update of this package was not requested

It seems your are using unsupported composer version.

Check the current composer version with:

composer -V

The 1.0.0 version of magento/composer-root-update-plugin requires composer-plugin-api ^1.0, so it's not compatible with Composer2. You can check out repository in more detail here.

If you just recently updated the composer you can run a rollback

composer self-update --rollback

Or install the latest release of version 1:

composer self-update --1

If you are updating Magento please check out the official documentation.

Hope this helps!


I was struggling with the same error recently. I downgraded composer to 1.9 and delete my composer.lock-file, it resolved that error you are having.

Downgrade composer:

  1. Uninstall composer
  2. Follow the instructions here: https://getcomposer.org/download/ with the excetion of using the download link for 1.9.3 (https://getcomposer.org/download/1.9.3/composer.phar)

Remove composer.lock file:

There is a file called composer.lock in your magento root folder. Delete it or move it just in case.

Then just run the command you did before.