I recently got a new phone OnePlus3 and trying to move my old messages from viber to the new one. The application doesn't support this process so I'm using a backup of the two applications along with the help from Android Backup Extractor. The process is described in the web so a google search would provide some more information.
The problem lies on the adb backup command as the package which is extracted from the device is kinda empty.
The old phone is a Nexus 4 with stock Android (rooted) version 5.1.1. The commands I'm using are:
The resulting file is 54 bytes in size and when I unpack it with Android Backup Extractor it's an empty tar file.
I've tried with adb version matching the one on the phone (version 32) and with latest (36) downloaded from the android SDK. I've also tried setting a password for backups and not use empty one.
Since I've been trying with no success I tried on OnePlus3 and on Nexus 5X with no results either. The final size might be different but it's the same issue either 0 bytes or 54 bytes. (which includes just the manifest file). Previously around X-mas I have done the process successfully and moved my messages from Nexus 4 to my Nexus 5X so it's either a new permission policy in Android or Viber application doesn't allow backups?
Happy to debug further if one has some suggestion.