The GPS on my Forerunner 45s won't work.

When attempting to start GPS tracking for mileage on my Forerunner 45s, I can't get passed the 'Wait for GPS' screen. It won't start. Then after a long period of time, the screen will just say "auto save" and return to clock face. I have only had this watch for 8 months. The problem began sporadically last month, but now the GPS won't work at all.