Having been waiting for Android Lollipop upgrade for several months on my stock but rooted Nexus 5 but nothing comes till yesterday. Google opens the door ajar allowing me upgrade directly to version 5.0.1 from current 4.4.4 in a particular time slot.

Can't hold my excitement and click "Upgrade and Install" button immediately. After 500MB upgrade downloaded, and restart, an "Error!" message flashes on the screen and droid robot is laying on the ground. More details output found on the next screen says:

"/system/vendor/etc/audio_effects.conf" has unexpected contents"

Google becomes merciless to people dare to break its house and make life a little bit easier them. Sigh ...

Googling solution for a few hours then find out two possible solutions:

1. Factory Reset a.k.a lost all your precious data
2. an unorthodox way of hacking

... ...

Someone says that good engineers are borne out of love of craft of hacking and the desire to let as many people as possible benefit from source of knowledge. 

Even I could risk losing the data and phone could become a brick, there is no way Google can weight its mighty power and stop me break its house again.

• Download factory images for Nexus Devices from https://developers.google.com/android/nexus/images

• Turn on Nexus 5 into developers mode, and connect it to PC via USB cable

• Run fastboot command and install Radio/Phone network image, install Recovery, Boot and System images in phone recovery mode. And reboot, fingers crossed. 

Image of rainbow on the screen spin, spin and spin ...

About 5 minutes later, screen says converting 247 applications into ART. God, thank you very much, let Google lost legal battle against Oracle on Java VM case.

Half an hour later, Lollipop lights up. A new world comes alive on Nexus 5.

First thing after upgrade?

Root it, again.