Can't Get ANY pop-up plug-in to work on blog

Hello,

Version 3.9.2 (USing WordPress for several years)

I am using a pop-up plug-in called “WordPress SimplePop Plus” and a theme called “Thrilling Theme”.

I am not able to get ANY pop-up plug-in to work (have tried at least 10 different plug-ins that I own).

What I have done:
Tried a different theme with the same result.
Currently have every other plug-in de-activated with no change.
Have tried pop-up plug-in on entirely different WP blog and it works fine.

Any suggestions would be greatly appreciated.

I have minimal (very little, ok… none) code experience.

Totally puzzled and need some direction,
Kevin Hauff