"Unable to Download"/"Unable to Install" on iOS app update
Whenever I try to update one of my apps, it downloads 79%, stops for a moment, then the progress bar resets and one of two dialog boxes appears:
Unable to Download Item
"App Name" cannot be downloaded. Please try again later.
[Done]
or
Unable to Download Application
"App Name" could not be installed at this time.
[Done] [Retry]
In the case of error #1, the app then returns to normal, but has not been updated. In the case of error #2, it sits at 0% and cannot be opened. Retrying simply repeats.
This does not happen with every app. Some apps simply install as expected.
I have a 4th generation iPod touch running the Evasi0n jailbreak of iOS 6.1. Rebooting does not resolve the problem, nor does launching in Safe Mode.
Solution 1:
When this happens to me, I find it starts because a download was interrupted.
To correct, I find it easiest to use my computer to install the update, which corrects each app it updates.
Solution 2:
I was able to recover from the error type #2 described in the question by deleting the /var/mobile/Media/Downloads/downloads.*.sqlitedb
file - where the asterisk matches some possibly random digits.
The file contains information about available (and partially downloaded) updates and the removal of the file causes the disrupted updates to become available again in the App Store. When you start App Store on the device, the file is re-created.
Now, it should be possible to update the apps that previously were caught in the failing update loop directly from the App Store.
Note, that deleting the file mentioned requires a jailbroken device with either iFile or some similar app or sshd
running on the device.