pptx files can't be opened when created with Impress 5.0.x

users
#1

Thanks for the link.

Unfortunately looks like the Kernel for PowerPoint Recovery tool is
not free (as in freedom) software, which is antiethical to
LibreOffice. Also, I think it is crucial that LibreOffice's export to
PowerPoint (.ppt or .pptx) function is as bug free as possible to
begin with.