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Can't read MSCDFileSystem


I get this error when opening pptx file in C#:

Can’t read MSCDFileSystem
The file is ZIP archive. It can be Microsoft PowerPoint 2007 PPTX presentation.

My code:

LoadOptions lo = new LoadOptions();
lo.Password = base.password;

pres = new PresentationEx(documentStream, lo);

Sample file is attached. Kindly note that it happens when there is no password (ie lo.Password is assigned blank ""


Hi Jay,

I have observed the presentation and code snippet shared by you along with presentation. Actually, you are trying to access the presentation with password options that is not actually password protected. If there is no password applied on presentation then you cannot use load options to load the presentation but rather use following code snippet to load it.

PresentationEx ppsd = new PresentationEx(file);

If in your application you are unsure whether a given presentation is password protected or not. You can use try catch block to load presentation. First try to load the presentation using above constructor of PresentationEx class normally. If the exception is thrown then in catch block try accessing the presentation with Loadoptions and set the password needed for that.

Many Thanks,