Hi, I have the following problem.

I try to export UltraWebGrid in PDF document, using UltraWebGridDocumentExporter. And I recieve an error.

Message:   Object reference not set to an instance of an object.

Source:     Infragistics35.WebUI.UltraWebGrid.DocumentExport.v8.2

StackTrace: "   at Infragistics.WebUI.UltraWebGrid.DocumentExport.CssClassCollection.AddStyles(UltraWebGrid grid)\r\n   at Infragistics.WebUI.UltraWebGrid.DocumentExport.UltraWebGridDocumentExporter.RenderDocument()\r\n   at Infragistics.WebUI.UltraWebGrid.DocumentExport.UltraWebGridDocumentExporter.Export()\r\n   at Infragistics.WebUI.UltraWebGrid.DocumentExport.UltraWebGridDocumentExporter.Export(UltraWebGrid grid, ISection section)\r\n   at Infragistics.WebUI.UltraWebGrid.DocumentExport.UltraWebGridDocumentExporter.Export(UltraWebGrid grid)\r\n   at UserControlDiscussionsGrid.Toolbutton(Object sender, ButtonEvent be) in d:\\OQProject_2008\\OverQuota\\UserControlDiscussionsGrid.ascx.cs:line 422\r\n   at Infragistics.WebUI.UltraWebToolbar.UltraWebToolbar.OnButtonClicked(TBarButton button, Boolean bDepressed)\r\n   at Infragistics.WebUI.UltraWebToolbar.UltraWebToolbar.RaisePostBackEvent(String eventArgument)\r\n   at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument)\r\n   at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)\r\n   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)" 

Target Site: {Void AddStyles(Infragistics.WebUI.UltraWebGrid.UltraWebGrid)}

Obviously the problem is when the styles are added, is there any limitations about the css classes and styles. If there is, can someone list them.

The columns in the grid are auto generated. 

Regards