I downloaded some previous versions and noticed the bug was introduced in the latest hotfix (2.5.12.0). Here’s some reproduce code (ppt-files are attached).
Presentation tpl = new Presentation(“template.pot”);Update: I’ve updated the attachment to include a presentation (test2.ppt) containing a slide with an embedded movie that also fails when running ChangeMaster.
Presentation pres = new Presentation(“test.ppt”);
Slide sld = pres.GetSlideByPosition(2);
sld = pres.CloneSlide(sld, 1, tpl, new SortedList());
sld = tpl.GetSlideByPosition(1);
sld.ChangeMaster(tpl.Masters[0]);