I own a Garmin Edge 800, it is very old but still super reliable. And the best part is that you can update the maps regularly via the OpenStreetMap initiative. It allows you to use turn-by-turn navigation and have an accurate view on the routes you are following.
This is the procedure:
Connect the device to your computer with the USB cable This should mount two storage devices on your computer: the built-in storage and the micro-SD card.
Open the zip file you just downloaded, and copy the file gmapsub.img to the Garmin folder on the SD card. Be patient, this took about 1 hour on my device.
On the GPS device, make sure to verify that the new map is the one that is active, especially if you have other maps on the card. There should only be one map activated. Check the readme.html file in the zip for more tips and tricks.
I recently had reset an older Apple TV (2nd generation) to the factory settings. After that, AirPlay did not work anymore. The Apple TV could not be found on the network (or example when trying to screen mirror from an iPhone), and when I navigated to Settings > General > About on the device, it showed Activation: failed
These are the steps I took to resolve the issue::
Make sure that you are signed in to iCloud on the Apple TV