Script inside a loop. error during 2nd execution

I have a package that runs a script task inside a loop.

public void Main()
{
                     int intCount;
                     intCount = (int)Dts.Variables["User::Count"].Value;

//some logic 

                     Dts.TaskResult = (int)ScriptResults.Success;

}

During the first iteration code works fine. during subsequent execution I get the below error if I try lookup the value of any variable in immediate window or quick watch 

Dts.Variables["User::Count"].Value
error CS1704: An assembly with the same simple name 'ST_850053c10abd463da6fd571ece4d8f95' has already been imported. Try removing one of the references (e.g. 'ST_850053c10abd463da6fd571ece4d8f95.dll') or sign them to enable side-by-side.