Keynote exports to PPSX instead of PPTX
I have a coworker using Keynote to export Keynote presentations to PowerPoint format. There are about 20 presentations in the series, all identical in visual style. However, presentation #7 exports as a ".ppsx" file which apparently cannot be edited in PowerPoint. All the rest correctly export as ".pptx" files.
According to one website, "PPSX is a PowerPoint Open XML Slide Show which was mainly designed to be non-editable and basically playback a PowerPoint presentation created prior. Files with the PPSX extension differ from PPTX which permits the file to be editable."
We are not sure why this one is exporting as PPSX, since the settings in the Export dialog are identical to all the other files. In fact, there is no PPSX export option, only PPTX. We also tried the legacy ".ppt" export option, but that saves out a folder with a ".pps" file inside (which is also apparently non-editable), along with some videos used in that presentation.
The coworker is using Keynote version 8.1.