I have an external API, the parameter is a file, in Mendix using Call Rest to call this API has been unsuccessful, from the console to see the following error ,anyone know how to resolve this ? thanks com.mendix.modules.microflowengine.MicroflowException: Error calling REST service at OCRRecognition.ACT_OCR_Upload (CallRest : 'Call REST (POST)') Advanced stacktrace: at com.mendix.integration.actions.microflow.RestCallAction.execute(RestCallAction.scala:79) Caused by: com.mendix.modules.microflowengine.MicroflowException: 400: BAD REQUEST at OCRRecognition.ACT_OCR_Upload (CallRest : 'Call REST (POST)') Advanced stacktrace: at com.mendix.integration.actions.microflow.RestCallAction.checkStatusCode(RestCallAction.scala:117) Call Rest Action Setting as below : External API :