iTunes could not backup iPhone because the iPhone disconnected

Hi,mr.Lawrence,i have iphone6 128gb and my laptop not see the phone on 'my computer'(or few times when i connect he see and dissapeared after 1 minute).Wanted to do backup on itunes,and when i started,after 1 or 2 minuts i see itunes cant backup,because iphone was disconnected.I tried the same with iphone 5,brother's iphone 6 64gb and ipad Air 5 and all work perfectly.Maybe you can help?Already thanks for answer.I have on my iphone 70000 photos,can be this what cause problem?

Also i recognised that most tme this 'ophone disconnected' happen near end of backup.What i can do?

This worked for me:Reset the Lockdown folder in iTunes - Apple Support

These 6 steps may work for you: If you can't make an iTunes backup of your iPhone, iPad, or iPod touch - Apple Support

If not, then you will have to perform the 7th unlisted step that worked for us: Go into iTunes > Preferences > Devices, and delete all of your previous backups.

I Just found out how to fixed this problem !

1- go to

Then check 'Null' app into

as u can see like in the picture ! Look at the Null version !

then go to App Store > Update > purchase > not on this phone > then find the app ( version ) that match to the "Null" version then re-install it ! After that check on ur storage if it a right app or not ~ if do ! U can delete that app and then 'Null will be gone '

There is no such 'Null' app on my device.

Hate to necro but it seems a lot of people have this problem and I wanted to share what ended up fixing the problem for me.

I tried everything in this thread and some others but what eventually made it work for me is plugging my phone into another computer and doing a back up on my brand new phone. After backing it up on a secondary computer I returned to the first, initially itunes wouldn't register my phone so I moved it from a USB 2.0 to a USB 3.0 on the front hub( yes I know this probably isn't relevant but hey it's what I did.) iTunes then recognized my phone and I tried to restore from my back up and it went flawlessly. I don't have any idea why this worked but it did, take it for whatever it's worth.

This came as a surprise at this point actually and my next move was to go into DFU mode and restore the phone and then try to restore from the back up. I received both the iPhone disconnected error as well as the iPhone back up session failed error. (Error code varied as I tried different things to solve the problem.)

Some background on my actual situation was that my phone 95% of the time would begin the restore for no more than 10 seconds and then the phone would restart and iTunes would say iPhone disconnected and cancel the restore.

Again this was a brand new phone and Apple if you are reading this I am not ruling out user error on my part. I'm not sure why this occurred but if I had to guess my first thought is that this stemmed from me doing an iCloud sync in the store before coming home and then trying to restore from a newer back up (The iCloud back up was really old and I have no idea where it came from.) Other thoughts of mine would be that I was running iOS 8.4 when I backed up the phone and maybe something has changed and caused a problem for me, but in the end I found it odd that simply backing it up and then trying to restore fixed my problem so easily. I feel almost as if the phone wouldn't restore from the back up until after it thought it had been backed up. Maybe there are reasons for safeguards like that to exist but I am far from knowledgeable in regards to theft and other devious things.

Hope this helps someone.

BIG thanks for the writeup. I'll try the 'other Mac' route...

I had a similar problem. I have my automatic backup set to iCloud, but I sometimes like to backup to the computer (e.g. if I'm about to get a new phone or take the phone in for repair). I connected iPhone to the Mac and manually clicked "Back up Now" but kept getting the disconnect alert.

I deselected options to auto sync and to sync with the phone over wifi, but neither fixed the problem. Finally, I switched the auto backup to this computer, leaving encryption on and leaving those two options unchecked. The backup then worked and I went back to automatically backing up to iCloud.

iPhone 5s/iOS 9.1, MBP early 2011/El Capitan 10.11.1, iTunes 12.3.1.23,

Top Man .... Many Thanks 🙂

So resetting the network settings on the phone can work one time and then fail for subsequent backups until reseting them again but I just found another workaround without having to reset network settings on the phone. Try booting your mac into SAFE MODE by holding SHIFT key at startup. Worked like a charm. It keeps 3rd party additions from booting with the system software. I wonder what applications installed all of us have in common. hmmmmmmm.

I don't believe it has something to do with 3rd party software on the Mac.

Tried to backup my iPhone on three different Macs - to no avail. Even set up an external drive / boot volume with a freshly installed OS X El Capitan (definitely no 3rd party apps installed). It simply doesn't work. Oddly enough backing up my iPad works like a charm on all three (four..) machines.

The root of all evils resides in our iPhones (or iPhone's software).

Did you try the safe boot?

I tried a long list of things to get iTunes to back up my iPhone 6 on my iMac. It would start the backup via wifi, or even USB cable, and stop 1/2 way in saying it disconnected. Rebooting the phone, Mac, disabling wifi, etc. all did not work. What did seem to work, is temporarily disabling the firewall in Norton Security on my Mac. Once this was done, backup seems to work just fine again.

Erik,

You are not the only one being plagued by this. I have had issues with iTunes and my iPhone/iPad backup for almost a year. Every so often it decides to fail backing up and I have to refer back to this article on deleting the old backup files to proceed. Apple has got some issues here. I'm currently on 10.10.5 with iTunes 12.2.3.35 and still have had the issue pop up recently.

My settings in iTunes are to encrypt the local backup since that's the only way for your passwords to be saved in the apps you've got installed. Otherwise when you purchase a new device and do a restore...you'll have to re-enter every password into every application all over again.