This error is very common, and I tried all of the solutions and non of them worked. I have disabled WebDAV publishing in control panel and added this to my web config file:<
For my part my POST handler was of this form:
[HttpPost("{routeParam}")]
public async Task PostActuality ([FromRoute] int routeParam, [FromBody] PostData data)
I figured out that I had to swap the arguments, that is to say the body data first then the route parameter, as this:
[HttpPost("{routeParam}")]
public async Task PostActuality ([FromBody] PostData data, [FromRoute] int routeParam)