What causes “The last backup could not be completed” error?

RickCMC

Suspended
Original poster
Sep 13, 2018
104
46
I was looking at iCloud and checked my backups and noticed an error message that said “The last backup could not be completed”. That’s all it said, it didn’t give any reason why it couldn’t be completed. I have never seen that message in all the years I’ve had iPhones. I was then able to backup manually without an error. But I was wondering what causes this error in the first place?
 

NoBoMac

Moderator
Staff member
Jul 1, 2014
2,848
1,183
Lost wifi connection while backing up? Mid automatic backup and pulled the device off power?
 

CTHarrryH

macrumors 68020
Jul 4, 2012
2,243
872
I get occasionally - never quite sure why - most of my backups are manual ones that I force. I find if I get that message I just restart backup and it works fine. Never sure if it is something running on my device or network error or iCloud issue but I do get occasionally. As I said making it restart backup works for me.
 

Minorite

macrumors 6502
May 8, 2018
493
116
Poland
It means that backup couldn't start/was interrupted for some reason. If you can back up manually and with iTunes then everything should be OK.
 

I7guy

macrumors Core
Nov 30, 2013
22,919
11,023
Gotta be in it to win it
Lost wifi connection while backing up? Mid automatic backup and pulled the device off power?
In my experience, it is this issue that occurs randomly. If I want to backup I plug the phone in, make sure it's off power saving. Then go into the icloud section of settings. The navigate to your phone and press backup now.
 

RickCMC

Suspended
Original poster
Sep 13, 2018
104
46
Now I’m getting a message that says “Some files were unavailable during the last backup”. Any idea what this means and how to fix it? I’m
 

spikeymike

macrumors newbie
Jul 6, 2010
28
13
Now I’m getting a message that says “Some files were unavailable during the last backup”. Any idea what this means and how to fix it? I’m
Been having the same issue for the past few days now.

I've tried logging out of iCloud and back in - no luck.
Deleting old backup and starting new one - no luck.
 

RickCMC

Suspended
Original poster
Sep 13, 2018
104
46
You mean you get this message when trying to back up manually?
I got that message after I had it plugged in and on WiFi and kicked overnight and then checked my iCloud backup. So it must have tried to back up automatically.
 

Minorite

macrumors 6502
May 8, 2018
493
116
Poland
And manual backup still works? If so, I would try to delete iCloud backup and do the manual one. Also if you have any VPN/Ad-Blocker running it can potentially affect iCloud backups, so check those. Also a good old reset to factory settings ususally fixes almost everything :)
 
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