I’ve reproduced the problem and added a ticket with ID SLIDESNET-43490 to our issue tracking system. We apologize for any inconvenience. Our development team will investigate the case. You will be notified when the issue is resolved.
Hi Stanislav,
We are coming across more ppts that are failing to save as pptx. I can share the other ppts in a day or two. But can we expedite this by moving this as a priority paid support ticket
The issues you have found earlier (filed as SLIDESNET-43490) have been fixed in Aspose.Slides for .NET 22.11 (ZIP, MSI).
You can check all fixes on the Release Notes page.
You can also find the latest version of our library on the Product Download page.