How to fix GTK theme on Qt 5.x apps Linux 10.12.2016

Install qt5-styleplugins

yaourt -S qt5-styleplugins

Install qt5ct

yaourt -S qt5ct

Set environment variable in /etc/environment

# sudo vim /etc/environment
QT_QPA_PLATFORMTHEME=qt5ct

Restart the system.

Start qt5ct and select gtk2 in Style.

Before

qt5_error.png

After

qt5_fix.png