There are a few causes why the popup won't activate and the list below shows the common mistake and solution:
1. Duplicate class
- In order for the custom Popup Activation to work you need to use a CSS Class but make sure that in the existing page where Popup Pro is used there are no duplicate of that CSS Class.
2. Custom Popup Activation only works with Images and iFrames
- You cannot do a Custom Popup Activation using a fileset or direct content in order to achieve this you will need to use the iFrame instead.