'App not Installed' Error on Android

Question

I have a program working in the Android Emulator. Every now and again I have been creating a signed .apk and exporting it to my HTC Desire to test. It has all been fine.

Answer 1

Clearly there are many causes of this problem. For me the situation was this: I had deployed to my nexus 7 (actual device) from within the Android Studio (v1.3.2). All worked fine. I then created a signed apk and uploaded to my Google Drive. After disconnecting my nexus from the usb, I went to the settings/apps and uninstalled my app (App1). I then opened google drive and clicked on my App1.apk and chose to install it (need to ensure you have allowed installation of apks in settings). Then I got the dreaded message "App not Installed"

Solution for me: go back into settings/apps and scroll though all apps and at the bottom was a pale version of my App1 (note the original App1 was at the top in Alphabetical order which was deleted as above). When clicking on the pale version it said "Not installed for this user". (I had set up my nexus to have more than one user). But in the top right corner there is a three dot button. I pressed this and it said "Uninstall for all users". Which I did and it fixed the problem. I was now able to click on App1.apk and it installed fine without the error.

Answer 2

Using Android Studio, I had previously installed the unsigned debug version of the APK (Build > Build APK) and had to uninstall it before installing the signed release version (Build Variants > Build Variant: release, Build > Generate Signed APK).

Answer 3

I had the same problem and here is how solved it : Go to the Manifest file and make sure you have the "Debuggable" and the "Test Only" attributes set to false. It worked for me :)

Answer 4

You also may encounter this issue because your device manufacturer did not license the Google commercial apps, such as Play Store, YouTube, Google Maps, etc. Follow this answer to solve the problem.

Answer 5

I had the same problem. I did not realise that an app must be signed even for testing.

After self signing it, it installed fine.

Answer 6

For those who are using Android Studio 3.

Suryanarayana Reddy's Answer is correct thought it doesn't state steps to solve it, hence.

in your AndroidManifest.xml under the application tag add testOnly="false" and android:debuggable="true" like so:

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:theme="@style/AppTheme"
    android:testOnly="false"
    android:debuggable="true"
    >

Edit
then in AndroidStudio's menubar Build > Build APK(s)