Unable to install anthropics/claude-plugins-official marketplace: Invalid marketplace.json: plugins.56.source

[Matonen]

Describe the bug

Unable to install the anthropics/claude-plugins-official marketplace using the Copilot CLI.
The command fails with a schema validation error related to marketplace.json.

Affected version

GitHub Copilot CLI 1.0.4

Steps to reproduce the behavior

1. Run the following command: copilot plugin marketplace add anthropics/claude-plugins-official
2. Command fails: Failed to add marketplace: Invalid marketplace.json: plugins.56.source: Invalid input

Expected behavior

Marketplace added successfully.

Additional context

It appears there have been recent updates to the marketplace.json schema.
A similar issue occurred in the Claude Code and was fixed here:

anthropics/claude-plugins-official#585

[lonetwin]

Also reported previously as #1287