title: write to powerpoint pptx from c# using openxml
body: <p>I am writing a data in to a pptx last slide using openxml in csharp and below is code to save the ppt</p>
  
  <pre><code>public static void CreateTableInLastSlide(PresentationDocument presentationDocument)
      {
          // Get the presentation Part of the presentation document
          PresentationPart presentationPart = presentationDocument.PresentationPart;
  
          // Get the Slide Id collection of the presentation document
          var slideIdList = presentationPart.Presentation.SlideIdList;
  
          if (slideIdList == null)
          {
              throw new NullReferenceException("The number of slide is empty, please select a ppt with a slide at least again");
          }
  
          // Get all Slide Part of the presentation document
          var list = slideIdList.ChildElements
                      .Cast&lt;SlideId&gt;()
                      .Select(x =&gt; presentationPart.GetPartById(x.RelationshipId))
                      .Cast&lt;SlidePart&gt;();
  
          // Get the last Slide Part of the presentation document
          var tableSlidePart = (SlidePart)list.Last();
  
          // Declare and instantiate the graphic Frame of the new slide
  
          P.GraphicFrame graphicFrame = tableSlidePart.Slide.CommonSlideData.ShapeTree.AppendChild(new P.GraphicFrame());
  
          ApplicationNonVisualDrawingPropertiesExtension applicationNonVisualDrawingPropertiesExtension = new ApplicationNonVisualDrawingPropertiesExtension();
          P14.ModificationId modificationId1 = new P14.ModificationId() { Val = 3229994563U };
          modificationId1.AddNamespaceDeclaration("p14", "http://schemas.microsoft.com/office/powerpoint/2010/main");
          applicationNonVisualDrawingPropertiesExtension.Append(modificationId1);
          graphicFrame.NonVisualGraphicFrameProperties = new DocumentFormat.OpenXml.Presentation.NonVisualGraphicFrameProperties
          (new A.NonVisualDrawingProperties() { Id = 5, Name = "table 1" },
          new A.NonVisualGraphicFrameDrawingProperties(new A.GraphicFrameLocks() { NoGrouping = true }),
          new ApplicationNonVisualDrawingProperties(new ApplicationNonVisualDrawingPropertiesExtensionList(applicationNonVisualDrawingPropertiesExtension)));
  
          graphicFrame.Transform = new Transform(new Offset() { X = 10, Y = 10 });
          graphicFrame.Graphic = new A.Graphic(new A.GraphicData(GenerateTable()) { Uri = "http://schemas.openxmlformats.org/drawingml/2006/table" });
          presentationPart.Presentation.Save();
  
      }
  </code></pre>
  
  <p>the file is saved with required data but 
  While opening the powerpoint I get the following error:</p>
  
  <p>Powerpoint found a problem with content in "Sample.pptx". Power point can attempt to repair the presentation.</p>
  
  <p>Once repaired, the content is shown ok. but since the file is corrupted when i run the code it is not updating with the latest data nexttime.
  Please help me to solve the issue</p>
  
  <p>-tried to open in different version of office but no luck
  -created the template from different versions still the issue occurs</p>