HTTP HTTP_AAE Content is not allowed in prolog

Hello Experts,

I have a litle problem with the HTTP_AAE adapter on PI. I'm sending request to the http service but the service returns only 0 or 1 without xml structure only 0 or 1.

So I created this mappnig:

And i get this message:

<SAP:Stack>Runtime exception occurred during application mapping com/sap/xi/tf/_JobsReqPostResponseMapping_; com.sap.aii.utilxi.misc.api.BaseRuntimeException:Content is not allowed in prolog. </SAP:Stack>

I tried create simple UDF, someting like this:

public String createResult(String result, Container container) throws StreamTransformationException {
return "<?xml version=\"1.0\" encoding=\"utf-8\"?><messageResp>" + result + "</messageResp>";
}

Could you please advice me?

Thanks Lukas Fridl.