Server Error in '/cloud' Application.

Value cannot be null.
Parameter name: input

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: input

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: input]
   System.Xml.XmlReaderSettings.CreateReader(Stream input, Uri baseUri, String baseUriString, XmlParserContext inputContext) +6609526
   SMathFileType.SMathFileType.(Stream , List`1 , FileContext ) +521
   SMath.Controls.DataFiles.(Stream , Worksheet , FileContext , & ) +1171
   SMath.Controls.DataFiles.OpenFileType(Stream stream, Worksheet worksheet, FileContext context) +179
   SMath.UI.Web.WorksheetExtractedData.LocateWorksheet() +407
   SMath.UI.Web.ObjectModel.Worksheet..ctor(Workbook workbook, WorksheetData initialData, WorksheetCreationData data) +269
   SMath.UI.Web.ObjectModel.Workbook.AddWorksheet(WorksheetCreationData data) +327
   SMath.UI.Web.ObjectModel.Requests.WorksheetAdd.Apply(Workbook parent) +52
   SMath.UI.Web.ObjectModel.Requests.WorkbookUpdate.Apply(Workbook target) +415
   SMath.UI.Web.ObjectModel.WorksheetGenerator.CreateWorksheet(WorksheetCreationData data) +241
   SMath.UI.Web.ObjectModel.WorksheetGenerator.CreateWorksheet(WorksheetCreationData data, String sourceId) +61
   SMath.UI.Web.FilesHandler.ProcessRequest(HttpContext context) +685
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +862
   System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step) +182
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +94

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.8.9191.0