Phone is a stock HTC Merge (ADR6325) running Android 2.2 (Froyo).
I purchased this phone from a VZW authorized retailer just before Thanksgiving, 2011. Have had no problems with it until recently.
The phone came pre-installed with the Kindle application version 18.104.22.16860055, which I had set to auto-update. It has apparently never done so, because two days ago it requested that I do a manual update of the app to version 3.5.1. After I download the app and it tries to install, I get an error: "Package file was not signed correctly. Uninstall the previous copy of the app and try again."
The problem is that I cannot uninstall the app because it was preinstalled on the phone and thus part of the ROM for the device. I have tried clearing the data and the cache for both the Play Store and the Kindle app (both separately and together), and the app still refuses to update.
Short of taking it to the VZW store I got it from or doing anything illegal/warranty-voiding to it, what other options would I have to update the app? It's an app I use very frequently and would like to get the new features provided in the newer version(s).
I apologize for the inconvenience you have experienced with the Kindle apps not updating. I checked my resources and did not find this to be a reported known issue with the HTC Merge.
You mentioned that you already tried clearing the data and cache for both the Play Store and the Kindle app. If the app is not updating one thing you can try is performing a hard reset on your device. This will reset your device back to the factory settings and then you can check if the Kindle app updates to the latest version or if it allows you to update manually. Below I have provide a link with the steps on how to perform the hard reset on your device.
Make sure you backup your device before the hard reset as this will erase all data on your phone.
Let us know if you need any further assistance after performing the hard reset.
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Just finished the hard reset function, let the phone re-program itself, and went to update the Kindle app before updating or downloading any other apps, thinking it could possibly have been a memory or RAM issue that is causing the problem.
Kindle was still showing as requiring a manual update from the original version, and would not automatically update to an intermediate version (say, 2.x) otherwise. After confirming that I wished to manually update to 22.214.171.124, I still received the same error as before regarding the package file.
Are there any other tricks I can try, or does this require a visit to a VZW store to attempt to remedy the problem (as a last resort)?
This does not work and you have several Merge users with same issues - please find us a fix - we have done as you asked and the Kindle app is still not updating and generating the message - "Package file was not signed correctly. Uninstall the previous copy of the app and try again."