How to fix "App not installed"?

Question

I have Galaxy S4 GT-I9500, plus I have much free space. Some apps have trouble to be installed which end after pressing "Install" and telling me "App not installed".

Please I need a solution for this weird issue.

Answer 1

This means the SD card hasn't been fully checked and mounted, and the app you're trying to run is on the SD. That's why you see the icon, but can't run it for awhile.

Answer 2

try disabling security checks in Security preferences Goto Settings-> More -> Security -> Uncheck Verify Apps and check Unknown sources

Answer 3

1. Summary

Try install your app via ADB → find information about error, that you get, in Google.

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2. Demonstration

«Почта России» («Russian Post») app in my case.

• Before:

• After:

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3. Disclaimer

Causes of App not installed in your case may be another, than in my example.

But the actions are the same as in Summary section.

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4. Prerequisites

You need:

1. Rooted device
2. Enable USB debugging
3. Install ADB to your PC; simple way in Windows — using Chocolatey

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5. Installation via ADB

1. Connect your Android phone to PC with enabling USB debugging
2. Download to PC apk file, that you can't install to Android

3. Try install your app from PC, use command:

   adb install <<path-to-your-app>>.apk
   

5.1. Example

D:\SashaDebugging\Android>adb install postal.russian-5.0.apk
* daemon not running; starting now at tcp:5037
* daemon started successfully
postal.russian-5.0.apk: 1 file push… 3.1 MB/s (5024614 bytes in 1.528s)
        pkg: /data/local/tmp/postal.russian-5.0.apk
Failure [INSTALL_FAILED_UID_CHANGED]

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6. Finding information about problem

I search in Google Failure [INSTALL_FAILED_UID_CHANGED] → I read most popular Stack Overflow answer → I navigate to data/data in my Android file manager → I find data of my «Почта России» app:

I delete selected folder → I try install «Почта России» again via APK Installer → installation was successful.