What Causes the “Check Your URL” Issue?
The “unknown error” message Downloader often throws out to new users is simply the app’s way of saying it can’t access parts of the Fire TV’s file structure necessary to complete the request. This is directly related to permissions, which Fire TV handles a bit differently than other Android apps. There’s really no way to prevent it, so if you run into the problem, just use the quick fix below and get back to sideloading.
Best Way to Fix the Downloader Error
First, back out of any apps and return to the Fire TV’s home menu. Go to Settings in the text menu at the top, then scroll right and choose the Applications icon. Inside, select Manage Installed Applications then move down until you see the entry for Downloader.
Open the Downloader menu item and scroll to the bottom. You’ll see a listing called Clear Data. Activate it and confirm your selection, then back out of the settings screen and launch Downloader again. You can simply head back one menu and click “Launch application”, or return to the home screen and launch from there.
Fire TV should throw a confirmation window at the bottom of the screen when you open Downloader after clearing the data. Choose “Allow” when you see the message above, then continue using Downloader as normal. You should be able to fetch and install apks without any kind of error.
If problems persist even after following the steps above, there are two more things you can try. The first is to uninstall Downloader and reinstall it from the appstore. Do this by navigating to Settings, then scroll right until you reach the Applications icon. Open it, select the Downloader entry, then move down and pick Uninstall. Confirm in the window that pops open. Next, head back to the appstore by navigating to Apps > Categories > Utilities. Scroll until you see Downloader, then re-install it.
If both of the above methods fail, try rebooting your Fire TV. Head to the Settings menu at the top of the main screen, scroll right and select Device. Move down until you see the Reboot option. Confirm and your Fire TV will automatically restart.