Error type: "Bad Request". Error message: "Invalid channel." Domain: "youtube.search". Reason: "invalidChannelId". Location type: "parameter". Location: "channelId".

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

Check in YouTube if the id UCpdnzJxKRpY1vKZWRZyfKkQ belongs to a channelid. Check the FAQ of the plugin or send error messages to support.