I have a Moto X running Android 5.0.1 and can't install an APK that i've received on my e-mail from a developer on my company.
I already researched a bit about this and none of the similar problems nor solutions worked for me.
What happens in my case is that i downlaod the APK from the e-mail, then go to the Downlaod section and try to install it.
- I can touch the "Install" button normally (no screen dimming app installed here) and the progress bar of the app being installed appears normally, as if the app was being installed.
- The option that allows me to install APKs from unknowns sources is also activated (in fact i managed to install other apps on this same smartphone the same way before).
After the progress bar screen i get a message that says "The app wasn't installed" (the original message is in portuguese, this is the most literal translation) and that is it. There is no feedback, no error message, no nothing.
When i try to install the same app but from the Android Studio (running the project on the smartphone) it runs sucessfully, but when i compile it into an APK and send it to be downloaded and installed, it doesn't work.