After one day I run Zenfone 4 with Kitkat, I’ve found a bug. Here is, you can follow me how I found the bug:
1. Hold Home button at the bottom of the phone
2. A Google circle button will appear, then press it
3. You will redirect to Google Now, right?
4. See what happen.
If you have an error, flicker, and unresponse screen with you can’t doing nothing, don’t worry we have the same problem. I don’t know if other vendor/phone have the same problem. Maybe it’s the bug. But it different if you access Google Now from normal menu, there is no problem. I hope the vendor release update soon.