Microsoft has this odd habit of changing one tiny feature, so that a newer versions file, does not work with an older version of the software, just to force upgrades. This could be as simple as changing a file version flag. Of course until the folks at LibreOffice get ahold of a few of these files and pull them apart, to see what the difference is, they can't support it either. <br><br>Unless you really need some feature from PowerPoint the ideal would be to export the PowerPoint slides as JPG files, and then load them into OpenLP as a group of images, and add that group to the service. If it's just text in front of a background, have them email the text, with indicators where they want the splits, and then do a custom slide deck in a lot less time, then to fight with PowerPoint. Often the only reason to use PowerPoint is it's fancy slide transitions, which are kinda lame anyway.