I’m getting an error when I’m doing calls (i.e. "getactivated couriers and get all couriers).

the error is

“callback”:“error”
“contextWrites”:{1 item
"to":{2 items
"status_code":“JSON_VALIDATION”
“status_msg”:“Syntax error. Incorrect input JSON. Please, check fields with JSON input.”

Just wondering what I can do to fix this and have the call working completely