Getting HTTP 415 Errors – What’s the Best Way to Fix Unsupported Media Type Issues? or HTTP 415 Unsup

http 415 usually means the server’s like "I don’t speak that language, bro."

Are you *sure* the endpoint expects JSON? Some older APIs want form-data or XML. Check the docs—or if there are none, try sniffing the traffic with Fiddler (fiddler2.com).