The error 800704CF generally occurs when the server is not in sync with your device. This can occur due to improper network connectivity or improper date and time.
Some common solutions are :
Set correct date and time manually
Try connecting via WI-Fi
Set install location of apps to Phone storage
Remove your SIM card and re-insert it.
The most common ...
This is a quite common issue if you are running the Insider preview and there is a work around.
The workaround allows you can to bypass error code 0x80073CF9 and successfully update the applications. Do the following:
Update the affected apps from the Windows Store
Wait for the update to fail and for error code 0x80073CF9 to be
Download via Wi-Fi and not cellular network.
Assure that you have the correct time and date.
Setting the correct time and date manually.
Install on phone memory instead of memory card (or vice versa).
Checked that your phone successfully runs its backups. If backup fails then Windows Phone can refuse to do several things, including doing update.
Might be this link will help you in rectifying the issue.
The solution described in the above link is,
Check your regional settings. Undo any changes you made recently.
Turn on your Location.
Check your storage sense. Make sure that the apps are installed to phone.
Soft reset your phone.
Hard reset ...
This appears to be a server-side issue, apparently many people are reporting the same error on both Windows Phone 8.1 and Windows 8.1. Nothing to do but wait for it to be resolved.
More information here: https://www.windowslatest.com/2018/12/10/the-windows-phone-8-1-store-is-broken-with-error-805a0193/
The phone you used to test, needs to registered for developing purpose , so that you can install apps outside of Windows Phone Store.
So unregister the phone you tested your app on, and try to install again from Phone Store.
Since I have updated on build 10.0.14393.448 the issue is resolved. Perhaps the initial build of W10M was unable to handle with that issue but the latest build is. As it resolved the issue for that phone and in another phone updated to the mentioned version I never encountered that issue. Thanks for everyone's efforts.
Some people suggest the problem may occur if you're using the SD card and then the phone crashes or runs out of battery. It's best not to have frequently used apps on the SD card. Also I fixed my problem by plugging the sd card into sd card reader on my laptop and running error checking there: http://www.ehow.com/how_6857598_check-sd-card-errors.html (...
The best solution I could find was to reinstall the app which is not possible in you case. You have also tried the next solution of resetting the phone.
Other than this here are some things you can try:
Go to Storage sense and change apps installation location to phone memory if it is set to SD card.
Make sure your region and time zone are same.
Check if ...