Add Example Response doesn't add required field

[JebediahSpringfield]

Hi,

When using Swagger Editor from master or 4.9.1, whenever I try to use the "Add Example Response", I get the error "fails with missingProperty: description".

I believe this is a bug, but I'm surprised that no one has reported it, so I might be missing something.

I'm using Windows 10, edge, Chrome and Firefox.

The only thing I need to do is hit "clear editor" add the basics to the API (Info, server, path) and add a response.

BR