bbmertz
Model Y
I updated my firmware last week from 4.0 and 4.2, it appeared to install successfully. Saw the release note screen after it was done. However the next day later I got a "Car needs service" contact Tesla message on my instrument cluster. The odometer was a bunch of dashes ----- mi and the GPS/Navigation wouldn't work.
I experienced similar issues after upgrading from 4.0 to 4.2, perhaps because it did not fully download due to marginal cellular reception. Unfortunately, my 17" screen also went black/non-responsive and had to be replaced by the service center, which I understand is not a common occurrence. I was told that it is fixed and working fine now, although I have not yet picked up the car.