Even i have same problem. Before updating plugin to latest one, sometimes it was showing video and sometimes it wasn’t. But after plugin update this error shows :
Error type: “Bad Request”. Error message: “Invalid channel.” Domain: “youtube.search”. Reason: “invalidChannelId”. Location type: “parameter”. Location: “channelId”.
Check in YouTube if the id UCp1o1m7WnXr6bl6oFVeVX9w belongs to a username. Check the FAQ of the plugin or send error messages to support
