A friend of mine’s IPhone would not launch apps that previously worked for him, which appeared to be 3rd party applications.  Here’s a few potential fixes with notes:

  • Download a new free app (like google earth) and once you enter your itunes password, all is fixed

Reason:

“Taken from another forum:
The reason this happens is because every time a downloaded app is opened it checks for your itunes password for validation that you are authorized to open that app (as it may contain personal info). From time to time the iphone “forgets” your itunes password. You can fix the missing password by syncing the iphone with itunes or downloading an app from the app store and entering your password that way.”

  • The solution for this situation was the Application setting tab at top when the iPhone is plugged in and iTunes is running. It seems when an iPhone ( the same may apply for iTouch also ) with 3rd party apps is plugged into iTunes , iTunes runs a backup to restore the 3rd party applications if needed. If the ‘ sync ‘ box ( for applications ) is unchecked and the sync is run , the apps are ‘ removed ‘ from your iPhone although they still appear on the iPhone ( similar to deleting a program but leaving the shortcut to it ). When starting the 3rd party app , it begins to run but then just exits.
    The fix for this was simply running iTunes , plugging in the iPhone and going to the Application tab and ensuring the ‘ sync ‘ applications box was checked ( along with all the applications it backed up under it ).
  • The solution for this situation was the Application setting tab at top when the iPhone is plugged in and iTunes is running. It seems when an iPhone ( the same may apply for iTouch also ) with 3rd party apps is plugged into iTunes , iTunes runs a backup to restore the 3rd party applications if needed. If the ‘ sync ‘ box ( for applications ) is unchecked and the sync is run , the apps are ‘ removed ‘ from your iPhone although they still appear on the iPhone ( similar to deleting a program but leaving the shortcut to it ). When starting the 3rd party app , it begins to run but then just exits.The fix for this was simply running iTunes , plugging in the iPhone and going to the Application tab and ensuring the ‘ sync ‘ applications box was checked ( along with all the applications it backed up under it ).
  • 1. Authorize, de-authorize and authorize again your computer in Itunes.
    2. Sync all apps – chose ’specified apps’ and check them all for sync (the third party apps still won’t work at this point).
    3. After syncing, with the IPhone still connected, delete one third party app (you’ll notice this app will lose its check).
    4. Recheck this app in Itunes and (with all the other apps checked as well) sync again.
    5. With the Iphone still connected, try opening the app you just restored. It should work fine, no saved data lost.
    6. Test your other apps. If still not working, try repeating steps 3 – 5 with other third party apps until it fixes the problem. It took me 3 deletes/restores to get everything running again.

Hopefully one of these solutions works for you.  I hear there’s good success with the install a new app solution.

–Ben

Source:  Iphone App Ratings Forum

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