swagger .net core API ambiguous HTTP Action debugging

Question

Implementing Swashbuckle/Swagger with .net Core 2 API I am now receiving the 500 error when accessing swagger.json:

NotSupportedException: Ambiguous HTTP

Answer 1

This can occur when a method is declared public in a controller, but without REST attributes. Changing the method to protected may address the issue.

I have seen this error before and usually the errormessage points to the culprit: EBisAPI.Controllers._class.HandleError

I guess HandleError is a public method in your base class, right? Change it to protected and try again.