First, a little background. Our players are designed to play all non-web content through temporary internet outages. All images and videos are downloaded to the local device and are then played from its local storage. This means that if you are not playing any web content, your screen will continue to function as normal on the display even if it is offline. Offline in our sense means the device has appeared to lose internet, and/or lost the ability to reach our cloud services (hasn't sent a heartbeat to our servers in a few hours). What this means is that the device will still show content just fine on the display, but that we have no way to provide updates, change content, or confirm it is functioning okay. This also means any remote commands would also not work, such as sending a reboot (this would require internet).
This can happen of course if the internet is down, but other reasons could include one of our services on the device having issues, or problems with your device's SD card, Other less common, more advanced issues could include improper or missing firewall rules, or even wrong VLAN assignments. The best way to find out more information would be to collect logs and send them to our team. If you're unable to do this at that time, then sometimes a quick power cycle can help if it was just an issue with one of the services. This can help restart services to get things moving again if there is not a deeper issue. This can be done by simply unplugging the power to the device, waiting a few seconds then connecting it back in.
Feel free to reach out to our team if you need any assistance!