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 18.104.22.168, 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)?
Same problem here. Any fix yet?
I'm having the same issue. It trys to update all day. Getting on my nerves. I've try everything short of rooting my system to get rid of it. This is not a new problem it is all over Google that others are having this same problem with their HTC Merge...
I am having the same issues with my Android Merge and I did all the things you recommended - it is very aggravating - please get us a fix soon!
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."
That error message usually happens when a modified version of the app is installed. This can happen if an app is themed to match the look of the phone's UI. Not sure if this is the case, but it sounds like it's something similar.
I haven't done anything to my knowledge to install any modified versions of this app. I would uninstall it and start over but it came loaded with the phone. Thank you for trying.
Yeah, it very well could have been modified by HTC, but I don't know why they would have done that.