Drill Through not working in SpagoBI server in birt report

Question

This is the setting of the hyperlink in birt report

The script used to compute the param is as follows:

if (params["idContratto"].match(row["contract_number"].toString()) == null){
    if (params["idContratto"].value == "abc"){
        row["contract_number"].toString();
    }
    else{
        params["idContratto"].value + "," + row["contract_number"].toString();
    }
}
else{
    if (params["idContratto"].length == row["contract_number"].length){
        "";
    }
    else{
        temp = params["idContratto"];
        temp = temp.replace(row["contract_number"].toString(), "");
        if (params["idContratto"].indexOf(row["contract_number"].toString()) == 0){
            temp = temp.replace(",","");
        }
        else{
            if (params["idContratto"].split(",").length == 2){
                temp = temp.replace(",","");
            }
            else if (temp.length == params["idContratto"].indexOf(row["contract_number"].toString())){
                temp = temp.substring(0,temp.length-1);
            }
            else{
                temp= temp.replace(",,",",");
            }
        }
        temp;
    }
}

Drill -through feature in birt report in spagoBI.. I have created a birt report using drill- through in spagoBI studio, It is running fine there, while deploy it on server. It is showing the error

-An error has occurred. Retry later. If the problems persists, contact the system administrator.

The url which is shown on the hyperlink is

"GET /SpagoBIBirtReportEngine/run?__report=%2FD%3A%2FAll-In-One-S‌​pagoBI-5.1.0_2101201‌​5%2Fbin%2FRevenueDet‌​ails.rptdesign&idCon‌​tratto=77&__overwrit‌​e=true HTTP/1.1" 404 687.