- This is Microsoft.
 - He returns Webhook success with a code 200 and plaintext 1.
 - He returns Webhook failure with a code 200 and a string tells its endpoint returned error 400.
 - the string didn’t tell what exactly the error.
 - Don’t be like Microsoft.
 
EDIT: Got a few details wrong since this happens a few months ago and this meme used to be on r/ProgrammerHumor. Also the proof: 


Yeah, typical on .net too. I just have a middleware and turn it into proper REST. Though all the error messages are usually like ‘something went wrong’.