When you update an iOS app on your iPhone, iPad or iPod touch you should experience a remarkably seamless move from the old version to the new. You go to the App Store app, tap the UPDATE (or the UPDATE ALL) button and, generally speaking, everything Just Works™. You don’t get asked to re-start your device “to complete the update”; you don’t even get asked to shut down (or even stop using) the apps you’re updating. It’s a great process.

Most of the time, anyway…

Unfortunately, this process isn’t always completely error-free. Sometimes, the file that contains the new version of the app (which is produced by Apple from the binary code the developer has uploaded for approval) doesn’t get made quite right. The app will run just fine for new installations, but updates don’t work correctly—typically, the updated app crashes straight after launching. These problems have always cropped up fro time to time, but they do seem more common since the recent launch of iOS 6.

So what do you do if you’re having this problem with updates on your recently-upgraded-to-iOS-6 device?

Start by making sure the app has been shut down completely, and then deleting it from you device.

To shut down an app (even one you think has crashed terminally), double-tap the main Home button on your iDevice to reveal the multitasking bar. Then press and hold on one of the icons you see there until they start to wobble. To shut down an app, you can then tap on the minus sign in the red circle that appears on the app in question.

Deleting the app is similar. Press the Home button once (to return to the Springboard—iOS’s “home screen”) and locate the app you want to delete. Press and hold on its icon until, again, the icons on the Springboard start to wobble:

This time you press the “X” on the black circle that appears. There will be a short pause and then you’ll see an alert:

This is important. If you’ve saved any files in the app’s private documents folder—in the case of 645 PRO, shown here, that may be some TIFF images—you should cancel and then do whatever’s necessary to save the documents you want somewhere else (with 645 PRO, that would mean copying the documents on to your computer using iTunes File Sharing, as explained here). Do be aware, however, that deleting the app doesn’t affect any files saved to a common area—so photographs saved to Camera Roll will be untouched.

Assuming everything’s fine, confirm the deletion—the app is now gone from your device.

The next stop is to do a clean install from the iTunes App Store. Go to the App Store app on your device, and select the Updates tab at the bottom, followed by the Purchased link at the top (if you’re using iPhone or iPod touch), or the Purchased tap at the bottom (iPad). There will be a pause and then you will see a list of all the apps you’ve ever purchased or (depending on which button is pressed at the top of the display) simply those that are not currently installed on your device:

 

Select the cloud button to the right of the app you want to re-install, and it should immediately start downloading and installing—indicated by the cloud changing to a greyed-out INSTALLING and then, once the installation is complete, OPEN.

Tap on that button again and you should find your app is working just fine!

The App Store’s app update procedure is elegant and well implemented, but nothing’s perfect—hopefully this will be of help if you do have a problem with it.