Unable to Post File along with other form data

We are unable to POST File(System.FileDocument) along with other values using form data in "Call Rest Service" activity.  when i debug in  server side i am unable to see file but other value are posted successfully.    When i call POST service from swager i can able to upload file successfully.     I tried following changes. 1. I put specific content-type for file field in Form Data 2. I try change to base64 encode / decode option. Still file name and file size not coming in server side.    Any one help here. 
1 answers

Mendix takes care of the required form-data headers, so there is no need to specify those yourself. Mendix also sends the binary contents and file metadata automatically. Did you specify your key and the correct FileDocument as the value?

This works for me.