'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

In my case it was because I was using the alpha version of support library 28. Looks like Google marks these pre release versions as testOnly. If you really want to release like this (for instance, you want to push an internal beta like I did), you can add this line to your gradle.properties file:

android.injected.testOnly=false