why am I getting a bad request error?

why am I getting a bad request error?

when I make a request with this information:

https://subscriptions.zoho.com/api/v1/hostedpages/updatesubscription

{ "subscription_id": "191134000000052059", "plan": { "plan_code": "25" }, "redirect_url": " http://www.disney.com " }

Your server returns a 400:

The remote server returned an error: (400) Bad Request.

Why?

It works in most cases, so is it something with that particular subscription id?