Error: 422 (Unprocessable Entity). Angular4

Question

I am trying to post data from Angular4 on localhost:4200 to an API on localhost:8000. I works fine with Postman, but not with Angular. Then I get:

Failed to load resource: the server responded with a status of 422 (Unprocessable Entity)

This is the service that posts to api:

This is the code that runs the method

   logIn(user: string, password: string){
      this.apiService.login(user, password).subscribe(
          data => console.log(data),
          error => console.log(error)
      );
    }

Answer 1

The 422 (Unprocessable Entity) status code means the server understands the content type of the request entity (hence a 415(Unsupported Media Type) status code is inappropriate), and the syntax of the request entity is correct (thus a 400 (Bad Request) status code is inappropriate) but was unable to process the contained instructions.

For example, this error condition may occur if an XML request body contains well-formed (i.e., syntactically correct), but semantically erroneous, XML instructions.