If you attempt to upload and convert a Slideshow and if it fails at slide 0, this guide will help you to get if resolved.
Instructions to Fix the Slideshow
Follow the steps below.
- Open the Slideshow in PowerPoint
- Go to the first slide
- Click the Insert menu and then click Textbox
- Click on the slideshow (anywhere) and type something
- Click the typed text to select it, and then right-click
- From the context menu, click Send to back and click Send to back from the options under it
- Save it and upload it.
If this does not work, add the text to all the slides and send all that text to back.