Adding an image to a slider

How can I add an image to a slider?
I have tried:
Dragging and dropping to the slide.
Dragging and dropping to the blank space below the slide after selecting the slide.
Pasting from the clipboard.
Adding media.

I’m using Master Slider ver. 1.0.5
in WordPress 3.9.1
in IIS 7.5
in Win7 Pro

I have looked in the documentation and it says everything except how to add an image to a slide.

Thanks,

Docfxit

https://www.ads-software.com/plugins/master-slider/