It's been a while since I've deployed an ADF Mobile app directly to my Samsung Galaxy S3; apparently since December of 2013. It was on that date that my mobile service provider upgraded my phone to Android 4.3 and in the process, turned off USB debugging.
It started with an unusual error message when I tried to deploy the app to my phone:
Technically, USB debugging was still enabled on my device, but the device certificates were lost, so as you can see in the screenshot, my device was on a USB connection, but it did not recognize my computer as a legitimate USB connection. Hence the unauthorized note listed with my device. Just for test purposes I turned off the USB function completely and got a slightly different error:
Both errors start out with "Failed to detect a connected Android device". A little bit of research led me to the solution which is quick and simple, though totally arcane and non-intuitive.
On your device, go to the Settings app and click on the More tab and then click on About device
Next, locate the Build number entry in the list and quickly click on it 10 times in a row. You should see a little message popup each time you click the list item.
Next hit the Back button and you should now see Developer Options listed in the More tab.
Click on the Developer Options list item and it will take you to a screen that allows you to re-enable USB debugging and accept new device certificates.