The flasher has failed. The flasher is a relay that turns the power to your turn signals on and off. On a motorcycle it could be buried almost anyplace on the wiring harness.
Go see the dealer. You should be able to get a replacement through their parts department. If they are a good friendly dealership they will tell you where it is located.
Once you find it replacement is usually easy. They just plug into the wiring harness. There may also be a fastener that attaches it so it doesn't vibrate.
