Error type: "Bad Request". Error message: "API key expired. Please renew the API key." Domain: "global". Reason: "badRequest".
Did you added your own Google API key? Look at the help.
Check in YouTube if the id PL4ow4vuWbnpnL8fPpm7VRG80250VGsb4- belongs to a playlist. Check the FAQ of the plugin or send error messages to support.