I am coming fro Openelec 6.0.3. Have done a backup with the option available in open elec. Stored the backup on a USB drive.
Did a fresh install on a fresh sd card. Restored it with the build in restoring functionality.
It is not working.
Now made backup with add-on backup, storing it on USB.
Fired up LE and tried to install Backup again. Do get an error message (look at logs). Just digging into it.