title: REST API call with 500 for few callers but for others works fine
body: <p>While trying to hit REST API by providing with necessary security credentials , the response is retrieved as 500-Internal Server Error. The log trace is been notes as ,</p>
  <p>Expression value is invalid. Specified value has invalid Control characters.    (or)
  Expression value is invalid. Specified value has invalid CRLF characters.</p>
  <p>This is not happening always but happens for few hits of the REST API particularly for few callers. Any idea/suggestion over here?</p>
  <p>Note: https call only. The REST API call is made via Azure APIM with policy code.</p>