"Add Item"-dialogue closes automatically after 2 seconds

[Trekbebbi]

Hello community

I skip the introduction of my first post and start right away with my fourth question:

Working with the "Advanced Theme Configurator", I wanted to add an item into the homeblock. But everytime I click on "Add Item", the dialogue box underneath pops up and closes itself again immediately. The same as I click the options of an existing item. Pops up and closes after about 2 seconds. No chance to click anywhere to make it stop disappearing. No matter, which browser I use, it's exactly the same.

 

An interesting Observation: If I activate the "CSS Magician - Ultimate Theme Configurator", the "Add Item" dialogue stays open, but the shop looks quite useless like that.