Why can't I add products to a discount in the admin panel?

[SGT1]

When creating a discount in my Admin. I am unable to select products to add.

In the applies to section of the discount page,  I search for products or collections and can select what I want. But there is no way to save the products or collections.

I click enter, and nothing happens; I click out of the pop-up window, and nothing shows up; I exit the pop-up window, and nothing works.

I was successful in doing this before with other collections.

[thechillydog]

I'm having a similar problem. For me the pop up window opens and there are products but when I select the checkbox for the product there's no way to close the pop-up and actually choose the product.