(400) Bad Request Error on Create Activity

We are getting (400) Bad Request Error while trying to create a new activity against person_id and deal_id. We are using C#'s HttpWebRequest to post our JSON to
with following body
“person_id”: “#####”,
“subject”: “Subject”,
“note”: “some html data”,
“deal_id”: “#####”,
“type”: “task”,
“done”: “1”
other than that instance our integeration is working fine. Another thing is that we are able to create activity on https://developers.pipedrive.com/docs/api/v1/ for this instance.
Please help us identify where things went wrong.

Hey @JonesSmith

Are you still having an issue with this?
I can’t see anything wrong with your code here, I would recommend just rechecking everything to make sure the syntax everywhere is correct. Otherwise, you can also shoot us an email or head to our support to share the code exactly as you have it.

The 400 (Bad Request) status code indicates that the server cannot or will not process the request because the received syntax is invalid, nonsensical, or exceeds some limitation on what the server is willing to process. It means that the request itself has somehow incorrect or corrupted and the server couldn’t understand it. The server is refusing to service the request because the entity of the request is in a format not supported by the requested resource for the requested method . Therefore, it prevents the website from being properly displayed. The main thing to understand is that the 400 Bad Request error is a client-side error.

The cause of a 400 error can be a wrongly written URL or a URL that contains unrecognizable characters. Another cause of the error might be an invalid or expired cookie. Also, if you try to upload a file that’s too large. If the server is programmed with a file size limit, then you might encounter a 400 error.