Failure [INSTALL_FAILED_PERMISSION_MODEL_DOWNGRADE]

Question

I entered the command below in the CMD and the command returned the error below the command.

Command:

phonegap run android --verbose --stacktrace

Error:

ERROR: Failed to launch application on device:

ERROR: Failed to install apk to device: pkg: /data/local/tmp/MainActivity-debug.apk

Failure [INSTALL_FAILED_PERMISSION_MODEL_DOWNGRADE]

Answer 1

The problem there, is that you are attempting to install a version of your APK that is LESS than what is already on your device.

Uninstalling will certainly fix that problem for you.

ADB allows more flexibility adb install -r -d <apk path>, but I am not sure that Phonegap has that functionality.

adb install [-lrtsdg] <file>
   - push this package file to the device and install it
     (-l: forward lock application)
     (-r: replace existing application)
     (-t: allow test packages)
     (-s: install application on sdcard)
     (-d: allow version code downgrade)
     (-g: grant all runtime permissions)

Update:

It turns out that was not the correct error message for downgrading the App version. Infact, it is something completely separate. I found this link that accurately explains the situation:

tl;dr You can't fool the new Android 6 permissions model by first publishing an APK with targetSdk 23 which will grant all permissions runtime and then publishing a new version with targetSdk 22 or less. You'll get an INSTALL_FAILED_PERMISSION_MODEL_DOWNGRADE error.

I was working on an app with targetSdk 23 (Android 6 Marshmallow) when it hit me that it possibly could be a security issue with the new Android permission model. Android 6 devices approves all permission on install time and then the user has to approve them whenever the app asks for the permission. What if the user installed the app - auto granting all permissions - and then it didn't ask for using them, and then afterwards the app was updated with the same permissions, but with a lower targetSdk?

I spent a couple minutes creating an app that targeted SDK level 23 and added a fine location permission (ACCESS_FINE_LOCATION). Then I installed and ran the app. The app didn't ask for permission to access the location manager. Then I set the SDK level to 22 and tried to install the app. Luckily it wasn't able to install. I got an error saying Failure [INSTALL_FAILED_PERMISSION_MODEL_DOWNGRADE].