iPhone won't back up to icloud:"Some files were unavailable during the last backup."

I just got off the phone with an Apple Support representative and she helped me to fix this issue. She advised that I press the Home button and the Power button for 10 seconds or until the white Apple sign appears. This will reset the phone. When I went back in and tried the icloud backup again it worked. I was so surprised it was so easy.

I turned the backup off, hit Ok here then turned it back on after a few seconds, then performed the backup again. It worked!!

I've had this same problem since upgrading to 10.3.3. Tried every solution that I could find but the error message still appears....

I should add, the problem appears with both my iPad Mini 4 and my iPhone SE, so it must be something to do with my iCloud account, not device settings

Thanks to keep me informed, but force restart is not giving any different result (in my case).

So I have the same mysterious message, but I can survive with this sitiuation (as I have already explained in my first post in this thread).

I use to officially backup my iPhone via iTunes, and somtimes I use iCloud only for partials backups, but Iìd like to have a definitive explanation about "Some files were unavailable during the last backup".

Regards

Giulio

Thank you for your report. But, again, nobody knows what that "error" message is related to.

As far as your "new question" is concerned, unfortunately I don't have any good answer to give you (I really don't know...but I can survive).

Regards

Giulio

Backup couldn’t be completed

Backup couldn’t be completed or you can’t restore

Backup couldn’t be completed or you can’t restore (2)

Backup couldn’t be completed or you can’t restore (3)

I turned the Backup off,

I've experienced the same issue, but after receiving that error message, i clicked again on "backup it now" and obtained a fresh backup.

Nobody here could give me an appropriate explanation, but this trick is working for me.

Please, keep me informed if you find a better solution.

Regards

Giulio

Backup couldn’t be completed

Backup couldn’t be completed or you can’t restore

Was having the same problem. Kept tapping on the "Back Up Now" but it kept giving the same error message, "Some files were unavailable during the last backup". I repeatedly selected "Back Up Now", but it always failed. I avoided resetting my iOS device. I also avoided deleting the iCloud backup.

I backed up my iOS device to my computer. Then went back to try, "Back Up Now" from iCloud->Backup settings. It failed, but this time, it deleted my previous backup. When I checked iCloud status, it indicated that there were no previous backups. I tried "Back Up Now" again and this time it successfully backed up my iOS device.

NEW QUESTION: Why does Apple sometimes refer to it as "Back up" (two words) and sometimes refer to it as "Backup" (one word)?

I've already read these artcles, but unfortunately that error message is not taken into consideration, and all the steps provided do not solve the issue.

Thanks anyway for your reply.

Regards

Giulio