Server Error in '/' Application.

String reference not set to an instance of a String.
Parameter name: s

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: String reference not set to an instance of a String.
Parameter name: s

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: String reference not set to an instance of a String.
Parameter name: s]
   System.Text.Encoding.GetBytes(String s) +7725105
   DrHussienV2.BusinessLogicLayer.CommonFunctions.ToUtf(String text) in E:\Ahmed Salah\DrHussienCode\DrHussienV2.BusinessLogicLayer\CommonFunctions.cs:82
   DrHussienV2.BusinessLogicLayer.DepartmentFile.get_FullFilePath() in E:\Ahmed Salah\DrHussienCode\DrHussienV2.BusinessLogicLayer\DepartmentFiles.cs:137
   DrHussienV2.Download.ProcessRequest(HttpContext context) in E:\Ahmed Salah\DrHussienCode\DrHussienV2\d.ashx.cs:42
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +181
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +75


Version Information: Microsoft .NET Framework Version:2.0.50727.9061; ASP.NET Version:2.0.50727.9062