This tutorial will teach you how to fix Invalid IPA or Installation Failed error on Installous on Jailbroken iPad 2, iPhone, iPod Touch 3.1.3, 4.3, 4.3.3. I was having this Invalid IPA problem on my iPhone 4 4.3.3 and it was really annoying. If you are having the same problem, follow these steps to fix Invalid IPA or Installation Failed error on Installous.
Re-install both Installous and AppSync on your jailbroken device. To do that, open Cydia. Then go to Manage and then to Packages. Locate AppSync and Installous and reinstall them. To see if it has fixed the problem, install any app and if it is installed successfully, you have fixed the problem. If the problem persists, restart your device and repeat the procedure. This should fix the invalid IPA error. Please let us know if you face any problem.