Powerpoint - Master Slide formats not following through to slides

Thanks for posting the link.

Your presentation makes a common mistake: all the placeholders on the slide master (the larger thumbnail above the slide layouts in Slide Master view) have been deleted. Those placeholders are parents to the slide layouts and without them, a presentation cannot function correctly. This concept is called "inheritance" and Office programs use it a lot.

The best practice is to format the slide master to look like the most commonly used content slide. Then make each layout a variant of that. Keep all the placeholders. Your design already has a slide number, footer and date, though you have tried to amalgamate the date into the footer. Use the built-in slide number, footer and date fields for that information rather than re-creating them. Here's my article on Best Practices in PowerPoint Construction with more information.

It may not be possible to rescue this file, you may have to start over. It can take longer to try to fix broken inheritance than it does to simply re-create the template.