I have made some changes to the existing map and tried to test the map. The Changes I made is adding a scripting fuctoid with the following code
public string Code(string recode, string amount)
{
double k = Convert.ToDouble(amount);
if(k>0)
{
return " ";
}
else return recode;
}
also added the logical functoid and value mapping in another field like

When I clicked the Test Map option, I am getting an error message like this

I am not sure what is going wrong. Can anybody help me with this.
Thanks