LG G4 User Manual page 278

NOTE
Your personal data from internal phone storage—including information about
•
your Google account and any other accounts, your system/application data
and settings, any downloaded applications and your DRM licence—might
be lost in the process of updating your phone's software. Therefore, LG
recommends that you backup your personal data before updating your
phone's software. LG does not take responsibility for any loss of personal
data.
This feature depends on your network service provider, region and country.
•
88
Phone software update