Cannot open pptx files from Office 2007

I wrote a little C# program attempting to open 2 simple pptx files generated from Office 2007. Both files failed with the following Exception:

System.Exception: Invalid header signature; read 1688935826934608, expected 162204723167

Attached please find a zip file that contains the C# source file and the two pptx files.

Please help! Thanks!!


Dear Charles,

Thanks for reporting, we will fix this bug as soon as possible and let you know.

Hello Charles,

You should use Aspose.Slides.Pptx.PresentationEx class to open pptx presentation.

Thank you very much for your reply!

A few questions:

(1) Urgent request: Slide and SlideEx are very similar. But Slide has GetThumbnail() but SlideEx doesn't? How do I get a thumbnail image from a SlideEx object?

(2) A suggestion: PresentationEx and Presentation do not share a common super class or interface? In fact, all classes in Aspose.Slides.Pptx do not share a common super class or interface with corresponding classes in Aspose.Slides For example,

For my application, I am processing a bunch of ppt and pptx files. It will simplify my code greatly if Presentation/PresentationEx, Slide/SlideEx, Shape/ShapeEx, etc, share some common super classes or interfaces, so that I can simply say:

PresentationCommonInterface pres = null;

if(filename.EndsWith("ppt")) pres = new Presentation(filename);

else pres = new PresentationEx(filename);

foreach(SlideCommonInterface slide in pres.Slides) {

Image img = slide.GetThumbnail(size);



Dear Charles,

Thumbnail functionality for pptx is yet to be added in Aspose.Slides.

Hello, Charles is out for a week. I’m the manager of the project he’s working on.

Do you have an estimate for when Aspose will provide the functionality of generating thumbnail images for pptx files?

One of the big features in our product is the ability to search slides and show a bunch of thumbnail images of the search results. A major goal for our upcoming release is adding support for Office 2007 file formats. So, any scheduling information you can provide would be quite helpful in determining what promises we can and cannot make to our customers.

We have an Aspose.Slides Developer OEM Subscription, SKU 1000370. Licensed to “SRI International”.

Steve Hardt

Dear Steve,

I have requested timeline for the pptx thumbnail feature and let you know as soon as possible.

Hi msfaiz, I’m looking into this issue as per Steve’s request, any news regarding get pptx thumbnail? Thanks. -Min


I work for a different company than the above posters, but we're encountering the same problem.

Please identify for us when ASPOSE slides will be able to pull thumbnail images from .pptx files. This is important to us, and we've placed trust in your company by building a product that utilizes your component under the assumption that pptx was a supported format.

Having reduced functionality for pptx files isn't a viable option for us.

Any answer would be greatly appreciated.


Please reply.


Please check the list of supported formats in the documentation. There is no pptx format.
Currently we have only experimental beta (I’d even say pre-beta) support for this format.
Thumbnails rendering can be provided just after full implementation of pptx reading.
So please don’t wait it in the nearest future.


Sorry to get in the middle of your thread but Alexey is telling to use the Aspose.Slides.Pptx.PresentationEx class to open pptx presentation. It's a short scroll above.

I downloaded the last version (I have an older aspose.slides) to see how my code would adapt and it is fine up to the getThumbnail method that is not supported.

I don't understand the statement above by Alexey that there is not PPTX format and the component is in pre-beta.

Please clarify if it is worth waiting for ASPose.slides to provide compatibility with PPT 2007 with at least the same interface available for PPT 2003 and a timeframe?

Thank you,


I never wrote that component is in pre-beta.
Only PPTX format development is in beta stage.
All other features are stable.

Okay! It's just confusing! PPTX development is in pre-beta then. But the following was said on March 29, 2008 hence the confusion.

*Hello Charles,
*You should use Aspose.Slides.Pptx.PresentationEx class to open pptx *presentation.

*Alexey Zhilin
*Lead Developer
*Aspose Tyumen Team

Do you have a timeframe or is it really far out?

Thanks :)

Hello, its been a year since my previous post, I thought I’d check again.
Is there any update on Aspose .NET support for thumbnails from .pptx slides?

P.S. We acutally found a workaround for our product for the last year. We used Office 2007 COM instrumentation to programatically convert .pptx files to .ppt. Then we run Aspose.Slides on the .ppt file to extract text and generate thumbnails. However, we now have customers where this workaround doesn’t work. So, we’d really like to get rid of the hacked-up workaround and just use Aspose directly.


Hello Steve,

Development of slides rendering for pptx format already started and
prerelease should be available at summer. Most probably in April.

Aspose team. My company is also waiting for pptx full support (including thumbnail creation, and also save as .ppt and save as .pdf).

Do you have a confirm outlook for having this functionality now?

Is any earlier release (e.g. without thumbnails, but with better pptx support) possible?


Aspose team. My company is also waiting for pptx full support (including thumbnail creation, and also save as .ppt and save as .pdf).

Do you have a confirm outlook for having this functionality now?


I am currently waiting for the same features. We are trying to use the GetThumbnail and SaveToPdf method to work for PresentationEx. These two methods work fine for Aspose.Slides.Presentation but not for Aspose.Slides.PresentationEx which support .pptx files. Please let us know when a Hot Fix will be available.


EF the Great!

Found this thread after posting a support issue… We are also trying to thumbnail from pptx but stumbled across errors… Any estimate on when support for this will be released?