Error type: "Forbidden". Error message: "Project 137163834978 has been scheduled for deletion and cannot be used for API calls. Visit to undelete the project." Domain: "usageLimits". Reason: "accessNotConfigured".

Did you added your own Google API key? Look at the help.

Check in YouTube if the id UC5fx1amwIwyXG7qdhDjXcKw belongs to a channelid. Check the FAQ of the plugin or send error messages to support.