I installed the Pop Up plugin 22.214.171.124 and set up my PopUp, when I purchased the premium plugin and upgraded to 4.5.1 my pop up breaks.
The dark overlay happens, the pop up shows for a split second and then disappears. I checked the CSS and the pop up box is set to display: none.
When I revert back to the 126.96.36.199 plugin everything works again. Has anyone encountered this before?