The document cannot be opened because there is an invalid part with an unexpected content type

Question

I am getting a error while opening using a presentation (PPTX files) creation code. Code i am using is given below:

  public static void UpdatePPT()
    {
        const string presentationmlNamespace = "http://schemas.openxmlformats.org/presentationml/2006/main";
        const string drawingmlNamespace = "http://schemas.openxmlformats.org/drawingml/2006/main";

        string fileName = Server.MapPath("~/PPT1.pptx");  //path of pptx file


        using (PresentationDocument pptPackage = PresentationDocument.Open(fileName, true))
        {


        } // Using pptPackage
}

and the error i am getting is:

"The document cannot be opened because there is an invalid part with an unexpected content type. 
[Part Uri=/ppt/printerSettings/printerSettings1.bin], 
[Content Type=application/vnd.openxmlformats-officedocument.presentationml.printerSettings], 
[Expected Content Type=application/vnd.openxmlformats-officedocument.spreadsheetml.printerSettings]."

error occurs at using (PresentationDocument pptPackage = PresentationDocument.Open(fileName, true))

Code works fine for many PPTX files. But it is throwing this error on some files. I am not able to find any solution. Thanks for your help.

Answer 1

Finally i have solved my problem. The PPTX i got was developed in mac os. So what i did is i just opened a working pptx file. And copied all the contents of not working pptx into working pptx and saved it by the name of not working pptx.

Answer 2

Old post, but I ran in to the same problem. I solved it programatically. Means:

My code runs using (var document = PresentationDocument.Open(fileName, true)) If this run into a exception I have a document like described. Then I call FixPowerpoint() method and do the other stuff after again.

Here is the method to share (using System.IO.Packaging):

private static void FixPowerpoint(string fileName)
{
  //Opening the package associated with file
  using (Package wdPackage = Package.Open(fileName, FileMode.Open, FileAccess.ReadWrite))
  {
    //Uri of the printer settings part
    var binPartUri = new Uri("/ppt/printerSettings/printerSettings1.bin", UriKind.Relative);
    if (wdPackage.PartExists(binPartUri))
    {
      //Uri of the presentation part which contains the relationship
      var presPartUri = new Uri("/ppt/presentation.xml", UriKind.RelativeOrAbsolute);
      var presPart = wdPackage.GetPart(presPartUri);
      //Getting the relationship from the URI
      var presentationPartRels =
          presPart.GetRelationships().Where(a => a.RelationshipType.Equals("http://schemas.openxmlformats.org/officeDocument/2006/relationships/printerSettings",
              StringComparison.InvariantCultureIgnoreCase)).SingleOrDefault();
      if (presentationPartRels != null)
      {
        //Delete the relationship
        presPart.DeleteRelationship(presentationPartRels.Id);
      }

      //Delete the part
      wdPackage.DeletePart(binPartUri);
    }
    wdPackage.Close();
  }
}