For the last few weeks, a conspicuous amount of Nexus Player owners have been reporting that their streaming boxes have up and stopped working. The devices become unresponsive, either hanging at the Google logo during startup or displaying an error message. Some users have been able to save their devices by flashing a new system image, but others haven't been so fortunate.
Seriously, there are a lot of reports. It's not entirely unusual for a device to decline as it gets on in years, but it is weird for so many to bite the dust in such quick succession. There are dozens of complaints, with some users claiming to have had several devices in their household go out within days of each other.
Devices that don't just fail to progress past the Google logo during boot display an error message that reads "Can't load Android system. Your data may be corrupt. If you continue to get this message, perform a factory data reset and erase all user data stored on this device." Several reports state that the suggested factory reset didn't fix the problem. One user says that manually flashing the most recent Android 8.0 Oreo system image from November 2017 didn't help matters, but the one from the preceding September worked. You can find the images on Google's Developer site.
It's unclear what's causing the recent rash of failures. It was confirmed in March that support for the Nexus Player had officially ended last year, so it's possible we may never know.