So I was trying to build my Google Cardboard app to an Android phone and I got this error.
This error can happen any time you build an app to Android from Unity. I was confused because I had tried all different USB modes, made sure the Google Drivers (as well as the drivers for this particular model of phone) were all installed to the latest versions. I couldn’t possibly enable USB mode any more than I already did. I restarted my computer and Unity a whole bunch of times and every time it would stop on this screen.
And give me that error above.
How to fix it
Apparently developer mode wasn’t enabled. But I didn’t see a setting to turn on development tools like I thought there would be. I knew there was a way to do it, but finding it was very difficult if you didn’t know what you were looking for.
Step 1. Go into your settings to where your Android version is listed. Should be somewhere in an “About phone” option.
Step 2. Tap the “Android version” until you see a dialogue box pop up at the bottom of the screen that says something along the lines of “Developer enables in *number* presses”. Tap that many more times and developer tools should be an option in your settings now. If you press it too many times you might see something like this.
I was extra confused since that isn’t the Android logo. Someone else pointed out it was a kitkat which is that build of Android.
Step 3. You should now see “Developer options” in your settings menu!