Not able to "Add to Project" after purchase from asset store.

Hi I bought the “Blocking Starter Pack” in the asset store and clicked “Add to project” and nothing happens. Also the drop down arrow isn’t clickable. I have contacted the author and he says its working fine for him, and the comments are saying its working on other peoples computers. So what could the problem be? I sorta think I haven’t fully dowloaded the pack yet but am unsure of how to go about that. Please help Epic! Id really love to use these assets in my game!