help - Rebuilding APKs

[harryk]

I've been trying to mod APKs by decompiling and rebuilding them. I tried using different sets of tools, but none of them seem to work. I tried using apktool and APK studio. Both can decompile and recompile the apk, and as long as i don't modify the source i can install the APK on my device after signing it. But if i make any change to the source such as changing

 if-nez v0, :cond_b

to

goto :cond_b

 

the rebuild process still works, but the rebuilt APK file can't be installed on the device. The 'Installing' screen is shown for a while, then it says 'app not installed'. The failed installation creates an empty folder in /data/data named com.<name of developer>.<name of app>, which I have to delete before trying to reistall.

 

Any thoughts on why the rebuilt APKs don't install?