SAP RFC Connection “Bad Variant Type”

问题

Well, 'm using SapConnector dll to make RFC from .Net to SAP. When I use dll in a Windows form application, everything is fine, but when I try to make connection in ASP.Net Web Site or Web Applcation a get an error;

Bad Variant Type

if (Connector.StartConnection())
    {
        try
        {
            Connector.AddFunction("Z_SCL_SOMETHING");
            Connector.AddFunctionInputParameter("WPERNR", "999999");
            Connector.CallFunction();
        }
   }

I get the error in this line;

Connector.AddFunction("Z_SCL_SOMETHING");

Another weird case is that, in Windows Forms Application when I make this call in backgroundWorker I get the same error again.

Any idea about this error ?

来源：https://stackoverflow.com/questions/14454574/sap-rfc-connection-bad-variant-type