Unable to cast object of type 'Aspose.PowerPoint.ppt.ac' to type 'Aspose.PowerPoint.ppt.m'

Hi

I’m using Aspose.PowerPoint 1.7.9.0 and have problem with a PowerPoint file. The presentation contains only one slide and it seems impossible to set a new presentation object. It working fine with all others presentation I have test with, and I can not see anything strange with this file.

Code:

FileStream fis = new FileStream(source, FileMode.Open, FileAccess.Read);
Presentation pres = new Presentation(fis);

Error message:
“Unable to cast object of type ‘Aspose.PowerPoint.ppt.ac’ to type ‘Aspose.PowerPoint.ppt.m’.”

What is the problem?

1.7.9 is too old version and I’m affraid I can’t help with it.
At first, try to update to the latest version. I think you shouldn’t have such problem after that.