Sony Xperia Z3 Compact Back and Home buttons not working Background

Many people have experienced a bug whereby the Sony Xperia Z3C (compact) no longer has functional home and back buttons. Specifically, the issue involves the buttons highlighted by the red rectangular box in the following image:



Problem

The problem may be caused by a number of reasons, from hardware issues to software upgrades. A solution is not easily found. As these buttons are essential for using the phone, when they are broken the phone is far less usable.

Workaround

A quick workaround is to rotate the phone "upside down" so that the buttons flip to the "top" of the screen.

Question

How do you fix this issue permanently?
Requirements

To fix the issue, you will need:


A laptop or desktop computer
A USB cable


Then:


Download Universal Android Debug Tools (ADB) onto the computer
Install ADB into C:\Program Files\platform-tools.


ADB is installed and the phone is ready to be fixed. Another SE answer has details on using ADB.

Instructions

A message on Sony's forum (since moved) offered the following solution:


Enable Developer Mode


Tap Settings > System > About Phone
Scroll down to Build Number
Tap Build Number about 7 times
Confirm Developer Mode, if prompted

Put the Z3C into USB Debug mode


Tap Settings > System > Developer Options
Scroll down to Debugging
Enable USB Debugging
Tap OK to confirm, if prompted

Plug the Z3C into the laptop or desktop computer


ADB must be installed before this step

Connect the Z3C to the computer using the USB cable
Confirm the connection, if prompted
Open a command prompt
Change to the ADB installation directory by typing:


cd "c:\program files\platform-tools"

Make sure the device is listed by typing:


adb devices -l

Change the overscan settings by typing:


adb shell wm overscan 0,0,0,30



The screen is shifted by about 30 pixels and the navigation buttons now work. It is safe to unplug the USB cable.