ASP.NET Core form POST results in a HTTP 415 Unsupported Media Type response

For forms, use the [FromForm] attribute instead of the [FromBody] attribute.

The below controller works with ASP.NET Core 1.1:

public class MyController : Controller
{
    [HttpPost]
    public async Task<IActionResult> Submit([FromForm] MyModel model)
    {
        //...
    }
}

Note: [FromXxx] is required if your controller is annotated with [ApiController]. For normal view controllers it can be omitted.