Exception: "The underlying connection was closed: The connection was closed unexpectedly." (sometime

Line 42:             catch (Exception ex)
Line 43:             {
Line 44:                 bool reThrow = ExceptionPolicy.HandleException(ex, "ReplacePolicy");
Line 45:         
 userprincipal.changepassword throws exception 
  
Hi all,
      userprincipal.changepassword(oldpassword, newpassword);
 gives error: that is Configuration information could not be read from the domain controller, either because the machine is unavailable, or access has been denied. (Exception from HRESULT: 0x80070547)
but userDirectoryEntry.invoke("ChangePassword", new object[] { oldpassword, newpassword });
      userDirectoryEntry.CommitChanges works fine. 
Any one please tell me the reason behind this.



 active directory exception unusual behaviour 
  
Hi 
i have a small problem
i want user names from active directory for an auto completer type of service
the method is always throwing an exception 
-------
"searcher.FindAll()' threw an exception of type 'System.DirectoryServices.DirectoryServicesCOMException'	System.DirectoryServices.SearchResultCollection 

 "Exception from HRESULT: 0x800AC472" 
  
Am Exporting Data in to Excel File,meanwhile if i open any other Excel 
file than the excel File on which am exporting data gets opened up 
Automatically having name Book1.How should i stop these excel file not 
to get open.In the Error log i get an error message showing " Exception from HRESULT: 0x800AC472" . Need help on these.Thanks in Advance.

 WebControls.TableRow throws exception on Add() 
  
I have the following method to strip hidden and user-specified columns from a gridviewrow and return a tablerow.  
    Private Shared Function StripHiddenColumns(ByVal gvRow As GridViewRow, ByVal ColumnsToExclude() As Integer) As TableRow

        Dim row As New TableRow
        Dim i As Integer = 0
        Try
            For Each cell As TableCell In gvRow.Cells
                If cell.Visible Then
                    If Not ColumnsToExclude.Contains(i) Then
                        row.Cells.Add(cell)
                    End If
                End If
                i += 1
            Next

            Return row
        Catch ex As Exception
            Throw ex
        End Try
    End Function
However, when I run this code and hit the Add method for the TableRow,  I get an InvalidOperationException stating the Collection was modified; enumeration operation may not execute.  I've gotten this exception before, but usually it's because I'm attempting to modify a table that is databound.  This particular one is not, i am creating it.  Can anyone offer any insight? 
Thanks in advance.
thefunnyman

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