[Android Q&A, Help & Troubleshooting] Dominekkas:
Hello there!

I am having problems with updating applications on my phone. I have a Sony Xperia S running on a custom ROM. Details of my phone are below. I can download or install an application from the market or from my internal storage, but afterwards I can not update. It only works sometimes on the market, but it never works when trying to update from my internal storage. I keep getting an "App not installed" error. I have 'Unknown source' checked. My phone is rooted with latest binary. I have the latest BusyBox. I have space in System, Data, Cache and Internal. I have tried multiple methods, such as Xposed' "Xinstaller" app, clearing cache and even data. I have also tried swapping android installation location just in case, because, well, you never know! I tried updating an app through multiple apps. But I had no luck there.

The thing is, I had this ROM before, and never had such problems. The ROM hasn't been updated since I last had it, so I know I am running on the same version. According to the developer, it's a stable ROM. I decided to move to Lollipop, only to find some incompatibility issues with a few apps, and eventually loosing my internal storage. So I had to reflash and all to get it even working. I have a backup of the ROM I ran with before going to 5.1.1, but that has some sort of boot problems, which I have caused. So I am sure its not the ROM itself.

I have not tried to replace an app file in my phones system-data folder manually, so I don't know if it works like that. I would like a more permanent solution, if possible. I don't want to uninstall and reinstall just to update. I would like to keep my data and not go through so much trouble. > Even if I had to I couldn't, because it wont let me. I have tried to uninstall an app and reinstall it with a newer version, but it simply won't let me, through my internal storage that is. Play has a mind of its own. Sometimes it would let me, sometimes it won't. Sometimes its just a specific app.

I have never met with such an issue ever. It's mind-blowing! :eek:

I have also tried searching this problem, but about 99% are about updating errors through Play. I have not contacted the ROM developer about this, as I think this problem is more universal.

Specs:

Manufacturer: Sony

Model: Xperia S

Android version: 4.4.4

ROM: Carbon-KK Unofficial (2014-11-03 1244)

Kernel: 3.4.0-Evolve-v1.25+ madhav@monster #1

CPU: ARMv7 Processor rev 4 (v7l)

Memory: 732 MB

Build Number: carbon_nozomi-userdebug 4.4.4 KTU84Q e6e5d96b44 test-keys

SELinux Status: Enforcing

I would appreciate anyone's help and suggestions!

#Edit:

After experimenting, I came to a conclusion.

I CANNOT give you an exact solution to this problem I've been having. It could be due to a faulty Xposed install or some sort. Maybe because I wasn't on the latest Xposed version. Or maybe because of Xposed' "XInstaller".

Try experimenting with basically what you have. Maybe I was lucky because I just had to remove an app. But you might not be. You could try to re-flash your ROM just in case it might be a system error, although that may be unlikely. Try removing or disabling (freezing) your app(s) that may cause you to have a signature error or any other app that may conflict an app install IN ANY WAY POSSIBLE. (Signature check, forward-locking, backward install, etc. (Just like XInstaller from Xposed))​

Hopefully many who might have came across this error will be able to get out of it with the above-mentioned.