Error type: "Forbidden". Error message: "The calling IP address 188.8.131.52 does not match the IP restrictions configured on the API key. Please use the API Console to update your key restrictions." Domain: "usageLimits". Reason: "ipRefererBlocked".
Did you added your own Google API key? Look at the help
Check in YouTube if the id PL2nizmytyS3-wOtrUkOBUyNlZq9yureMh
belongs to a playlist. Check the FAQ
of the plugin or send error messages to support