Windows 10 Movie Maker has intermittent movie saving problems

First time using Movie Maker.  For the most part I have zero problems saving a movie after creating the project. 

When saving a small dialog box pops up and says:

Saving Movie

Step 1 of 1

It then saves it.  Awesome.

However, sometimes when saving a movie the same dialog box comes up and says:

Saving Movie

Step 1 of 2

...and it never moves forward from there.

I don't know what the 2nd step would be and I am not knowingly doing anything any different that I would do on any other clip that I create when I'm getting only a 1 step save.  

Any ideas?