IO(Udp) SimpleSender has message size limits. What are they?

I keep getting the following debug logging from the Classic Networking IO(Udp) par of Akka.

09:11:16.029 [] DEBUG - Message too long
09:11:16.032 [] DEBUG - Closing DatagramChannel after being stopped

I can’t find anywhere in the documentation any statement on the maximum message length nor can I find “Message too long” in the code for SelectionHandler so my sleuthing for an answer is at an end. If someone can identify this for me, I would be happy to update the document with a pull request.

I would also like to know why the UdPSender is stopped as a result as this causes a complete failure of my application. Is it as simple as opting for a supervisor strategy that is “Restart” as opposed to “Stop” (Classic actors default)?