I have had this issue under various versions running on different pi3's. In the interest of full disclosure, i had similar issues under OE on several Chromeboxes.
Either the backup hangs requiring the power cord to be pulled or the backup finishes but the file refuses to restore.
Is there any easy solution for this? Is either any way to check the file after it has been completed to make sure that it will be able to be restored?
Alternatively, I guess that I could use one of the backup addons but I would prefer to use LE own.
Any suggestions will be greatly appreciated.
Thanks.