For some reason the latest version of the app that Amazon is pushing out is corrupted, right now to fix you must sideload the "real" app. see https://forum.silicondust.com/forum/viewtopic.php?f=119&t=74851 but that may not solve OP's original problem. What you have suggested is still not working an...

The latest update is just not getting installed om my Firestick 4K no matter what I tried. Uninstalling and trying to reinstall from official amazon store, downloading from the above link and even from official HDHomeRun source and sideloading it. I just keep on getting an install failed message. It...