It looks to be powered by Android so it's no wonder it crashes and freezes up every so often.
Apps crash and freeze, the touch screen stops working, music won't play, blanks screen, no sound. Take your pick.
Not to mention that turning the car off can be awkward and dangerous as you drive.
Something goes tits up in the system and it's not forgetting the problem any time soon.
The fix is pretty easy. The manufacturers were good enough to put in a hardware/software reset.
All you have to do is press the home button 5 times. (it's the one with the house symbol).
The stereo will reboot and hopefully the issue will be gone until the next time something goes wrong.