Failed to script out Dropping Default Constraint script for table columns

I used the following code to script out Creating default constraints. It works fine. But if I change so.ScriptDrops = true to script Dropping default constraints, it always fails with

Exception: {"Script failed for DefaultConstraint 'DF_Employee_VacationHours'. "}

InnerException: {"Object reference not set to an instance of an object."}

Can anyone shred some light on it? Thanks in advance.

using System;

using System.Collections.Generic;

using System.Collections.Specialized;

using System.Text;

using Microsoft.SqlServer.Management.Smo;

using Microsoft.SqlServer.Management.Common;

namespace Test2

{

class Program

{

static void Main(string[] args)

{

Server s = new Server(".");

StringCollection sc;

ScriptingOptions so=new ScriptingOptions();

so.ScriptDrops = false;

s.ConnectionContext.SqlExecutionModes = SqlExecutionModes.CaptureSql;

foreach (Table t in s.Databases["Adventureworks"].Tables)

{

foreach (Column c in t.Columns)

{

if (c.DefaultConstraint!=null)

{

Console.WriteLine(string.Format("{0},{1}", t.Name, c.Name));

sc=c.DefaultConstraint.Script(so);

foreach (string st in sc)

{

Console.WriteLine(string.Format("{0}", st));

}

sc = null;

}

}

}

return;

}

}

}

Hi,

Thank you for reporting this issue. This is a defect in SMO, and we're filing a bug report. We will try to fix it for the next release of the product.