Server Error in '/' Application.

Conversion from type 'DBNull' to type 'String' is not valid.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.InvalidOperationException: Conversion from type 'DBNull' to type 'String' is not valid.

Source Error:


Line 139:                End If
Line 140:            Catch ex As Exception
Line 141:                Throw New InvalidOperationException(ex.Message)
Line 142:            Finally
Line 143:                SqlConnection.Dispose()

Source File: D:\HostingSpaces\bostanabad.ir\httpdocs\App_Code\SqlCommandExecuter.vb    Line: 141

Stack Trace:


[InvalidOperationException: Conversion from type 'DBNull' to type 'String' is not valid.]
   Rssprovider.RSS.ReadParam(String Qr) in D:\HostingSpaces\bostanabad.ir\httpdocs\App_Code\SqlCommandExecuter.vb:141
   bostan._Default_Load(Object sender, EventArgs e) in D:\HostingSpaces\bostanabad.ir\httpdocs\bostan.master.vb:15
   System.Web.UI.Control.OnLoad(EventArgs e) +97
   System.Web.UI.Control.LoadRecursive() +61
   System.Web.UI.Control.LoadRecursive() +134
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +693


Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.8.4700.0