How to Fix an Invalid IPA on an iPad
Invalid IPA file prevents you from installing a downloaded application from the Installous app on a jailbroken iOS device, such as an Apple iPad. There is one particular cause that results in the “Installation Failed: Invalid IPA” error message — either you don’t have the App Sync add-on installed or it is out of date. It is easy to remedy this problem and you can successfully install IPA files immediately after employing this fix.
1. Tap the “Cydia” icon from the iPad’s home screen and go to the “Search” section inside the app.
3. Tap the “AppSync for iOS 4.x+” listing, then tap the “Install” button at the upper right corner and press “Confirm” on the next screen. Alternatively, if the app was already installed, press the “Modify” button instead of “Install,” then tap the “Reinstall” option. The app installs on your iPad and eliminates the invalid IPA error message you were having.