You mean you purchased something in the Store and would like to download that now ?
What browser are you using ? The Browser needs to start the Launcher as an external program to start the download. Try Firefox or Internet Explorer.
You can manually start the launcher first and then download. That sometimes helps.
I don't work or have any association with EA. I give advice to the best of my knowledge and cannot be held responsible for any damage done to your computer/game.
Please only contact me via PM when asked to do so.