EA App "Mandatory Update"

When I try to open my EA app, it says that there is a mandatory update that I have to install before I can open the app. I click restart and the downloading screen appears. It downloads rather fast, however, when it gets to the applying screen is stay at 0% and then a dialogue box pops up where it is verifying the ea app.app and when this is complete, the dialogue box disappears and nothing happens. When I open the task manager the EA app isn't running. I have the EA app installed on a USB because I do not have the space available on my Mac and have played my sims game successfully for a month now with everything on my USB.