Based on your HTML response, I can surely tell you that this is not the JSON. A response tells me that you have a incorrect URL for a web service.
You need to check the URL.
Also it looks like a simple answer is a right one - your result is not the valid JSON string. Please see JSON.org website for more details on what the JSON should look like.
Check out JSON Parser Online I know it is very useful when you are working with JSON.
It is very strange that you are requesting the JSON, and it is not returning it properly.
Remove your docType from API. and you must set content Type as Application/json . (because a text/html will not be read as json . so you were seeing the error.)