Server Error in '/' Application.

Value cannot be null.
Parameter name: connectionString

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.ArgumentNullException: Value cannot be null.
Parameter name: connectionString

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:


[ArgumentNullException: Value cannot be null.
Parameter name: connectionString]
   LibraryDM.Sql.NewConnection() +209
   LibraryDM.List.SingleList(String query, String whereQuery, String havingQuery, String orderQuery, HtmlTextWriter outputStream) +1229
   LibraryDM.List.Render(HtmlTextWriter outputStream) +15634
   System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +80
   System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +169
   System.Web.UI.Page.Render(HtmlTextWriter writer) +40
   System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +80
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +4239


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