I'm unable to customize the ringtone on my second generation Moto G after upgrading to Lollipop. I tried doing it normally from the Android settings, but just got a default "beep" sound instead. Only the built-in ringtone works properly.
Someone put this as an edit instead of an answer:
Instead of setting ringtone under setting --> Sounds and notifications, try to set your ringtone from your player [Ex: ES File Explorer --> sdcard --> download --> your song. Play this in ES media player --> set ringtone ].
and someone else tried to edit this in:
1- change ur choice music into .ogg format (try fx file explorer it may able to rename any format u want)
2- put that music file on the ringtone folder on phone where hangout ringtones are present 3-now power off ur phone and start it
4-go to phones and notification folder u got ur choice music as a ringtone