Yes, the updates have been problematic in the recent past.
We have observed unusual high traffic on the server which affects the updates of SNAP, especially in the time between 10:00 pm and 9:00 am CET.
So it might work if your try to reinstall later.
The traffic is not an attack, but there are unusual requests for the DEM files.
Probably, someone is processing a lot and is not using the cache for the DEM.
We are working on it.