After upgrading Jenkins from 2.249.2 to 2.277.3, webhooks being fired from github enterprise by way of the ghrpb started randomly failing with errors indicating that the payload was missing from the request. Messages were similar to below:
We saw similarly worded errors coming from the Github plugin as well.
The underlying error was exposed after enabling Jenkins logging on jetty:
Which further down in the stack indicated it was bubbling up from ghprb: