RDLC - Export to PDF

Question

Hi,
   I use RDLC  files for ReportGeneration.Here report successfully generated.It can be export in to Word and Excel.But when I try to export to PDF can't be done.

Can anyone give me the idea to solve this?

It will shows the following error:: 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.NullReferenceException: Object reference not set to an instance of an object.

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: 

[NullReferenceException: Object reference not set to an instance of an object.] Microsoft.ReportingServices.Rendering.HPBProcessing.TextRun.GetRichTextRun() +49 Microsoft.ReportingServices.Rendering.HPBProcessing.Paragraph.GetRichTextParagraph() +179 Microsoft.ReportingServices.Rendering.HPBProcessing.TextBox.GetRichTextBox() +556 Microsoft.ReportingServices.Rendering.HPBProcessing.TextBox.AddToPage(RPLWriter rplWriter, PageContext pageContext, Double pageLeft, Double pageTop, Double pageRight, Double pageBottom, RepeatState repeatState) +1408 Microsoft.ReportingServices.Rendering.HPBProcessing.RowInfo.AddToPageContent(ScalableList`1 columnInfo, Int32& colsOnPage, Boolean isLTR, Boolean pinnedToParentCell, RPLWriter rplWriter, PageContext pageContext, Double pageLeft, Double pageTop, Double pageRight, Double pageBottom, RepeatState repeatState) +940 Microsoft.ReportingServices.Rendering.HPBProcessing.Tablix.AddToPage(RPLWriter rplWriter, PageContext pageContext, Double pageLeft, Double pageTop, Double pageRight, Double pageBottom, RepeatState repeatState) +1967 Microsoft.ReportingServices.Rendering.HPBProcessing.PageItemContainer.AddToPage(RPLWriter rplWriter, PageContext pageContext, Double pageLeft, Double pageTop, Double pageRight, Double pageBottom, RepeatState repeatState) +679 Microsoft.ReportingServices.Rendering.HPBProcessing.Report.NextPage(RPLWriter rplWriter, Int32 page, Int32 totalPages) +1687 Microsoft.ReportingServices.Rendering.HPBProcessing.HPBProcessing.NextPage() +91 Microsoft.ReportingServices.Rendering.HPBProcessing.HPBProcessing.Init(Report report, PaginationSettings pagination, CreateAndRegisterStream createAndRegisterStream, Hashtable& renderProperties) +307 Microsoft.ReportingServices.Rendering.HPBProcessing.HPBProcessing..ctor(Report report, PaginationSettings pagination, CreateAndRegisterStream createAndRegisterStream, Hashtable& renderProperties) +96 Microsoft.ReportingServices.Rendering.ImageRenderer.PDFRenderer.Render(Report report, NameValueCollection deviceInfo, Hashtable renderProperties, CreateAndRegisterStream createAndRegisterStream) +226 Microsoft.ReportingServices.Rendering.ImageRenderer.RendererBase.Render(Report report, NameValueCollection reportServerParameters, NameValueCollection deviceInfo, NameValueCollection clientCapabilities, Hashtable& renderProperties, CreateAndRegisterStream createAndRegisterStream) +98 [LocalProcessingException: An error occurred during local report processing.] Microsoft.Reporting.WebForms.LocalReport.InternalRender(String format, Boolean allowInternalRenderers, String deviceInfo, PageCountMode pageCountMode, CreateAndRegisterStream createStreamCallback, Warning[]& warnings) +606 Microsoft.Reporting.WebForms.LocalModeSession.RenderReport(String format, Boolean allowInternalRenderers, String deviceInfo, NameValueCollection additionalParams, Boolean cacheSecondaryStreamsForHtml, String& mimeType, String& fileNameExtension) +277 Microsoft.Reporting.WebForms.ExportOperation.PerformOperation(NameValueCollection urlQuery, HttpResponse response) +292 Microsoft.Reporting.WebForms.HttpHandler.ProcessRequest(HttpContext context) +233 System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +100 System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +75