Qt applications (QWidget or QQuick 2) won't start on Android 4.4. I get the following output:
I/Qt ( 1080): qt start
F/Qt ( 1080): Can't find method "mNativeSurfaceI"
F/Qt ( 1080): registerNatives failed
This happens on the Android 4.4 emulator image and the Nexus 5 device. Using devices with previous versions of Android or emulator images other than Android 4.4 works fine.