Q: "Error -50". Can't update iphone 4 to iOS 5.

Sorry when I said stops at 15% i meant thats when error -50 keeps coming up. It happens at the same spot everytime I try to upgrade. It syncs fine just cant seem to upgrade just keeps coming up with error message. I have tried terminal method, force quit iTunes, master reboot but nothing seems to work

This is a solution that has worked for me and several others...

defaults write com.apple.iTunes DeviceBackupsDisabled -bool false

try it

The external drive might be the problem.

Can you try configuring iTunes to run from the local drive and see what happens? You can configure it back afterwards.

Seriously - this works most of the time - just reset the backup pref instruction...

defaults write com.apple.iTunes DeviceBackupsDisabled -bool false

Madpie, I've just realised, my iTunes is set up to store everything on an external drive, it was fine for me once I type that line into the terminal.

Are you sure you're typing it in exactly as it says in previous posts? I did a copy & paste when I did it. And you are definately typing it into the terminal?

Is there any way you can upload a screen grab or video clip to show exacly what's happening?

tasiv wrote:

 

Yes, you are a genius.  "defaults write com.apple.iTunes DeviceBackupsDisabled -bool false" 

works! Publish far and wide. Even Apple "senior" advisors had no idea about error -50.  Thank you, thank you!

The problem with the -50 error is that it has always meant "Parameters error" in the Mac world, so it's certainly a meaningless description (and cause).

I'm just wondering what does DeviceBackupDisabled enables when it's set to false.

Gotta love meaningless error msgs (-50) and apparently Apple has not discriminated between either Mac or PC, both seem to be getting these error -50 messages.

As to your question, the default setting for DeviceBackupDisabled is actually "False".

This enables the automatic backup of your iPhone/iPod Touch/iPad. When you set it to "True" you disable the automatic backup...

Seems like reverse logic to me, why not name this 'DeviceBackupEnabled', oh well...

I came across this setting back in the day when I still had iOS 4 on my iPhone 3G. I had changed this setting to "True" because a backup of the iPhone with each sync would literally take an hour or so...

I even wrote a small AppleScript application to toggle this setting between "True" and "False" easily so I could occassionally make a backup, just not all the time...

Too bad that the iOS Upgrade process in iTunes does not properly check for this exception and instead throws this generic error, maybe this will get addressed in a future version of iTunes, we can only hope.

So people who run into this thread looking possible solutions to error -50, if you have this on a Mac, there is a good chance the  "defaults write com.apple.iTunes DeviceBackupsDisabled -bool false" solution may work, however since the error is generic, there may be a different reason you're getting this...

brother you rock..my iphone backup works again..tnx

Hello

I have done the terminal steps but actually i am getting (command not found). Still getting the (-50) error which is *****. any other solutions?

Did you copy and paste when you did it?

I think that error is normally to do with a filepath problem. I could be wrong.

How is Madpie getting on?

I Tried by "copy and paste" and by writing it.

Did you manage to sort it?

If not, can you upload a screen grab?

Madpie, if you're still reading this thread and still having problems, the line you have to type into Terminal is case sensitive. Probably best to copy and paste.

THANK YOU SO MUCH! I HAVE UPDATED TO iOS 5.1.1! THANK YOU!

hey can you help me? I have one iphone 4s 16gb but when i try upgrade appear erro 50, i tested the motherboard on other iphone and still the problem, i upgraded other iphone on the same pc and it's fine, i don't have problem but when i try with mi iphone appear the error 50 again!... please help me!