Fix ITunes Error 3503 IOS 11 Update and Restore

iPhone users are trying to Restore/Update to the newer IOS 11 using iTunes and facing the weird error in iTunes which is 3503, here in this guide I am going to explain possible solution to this issue.

People are asking Questions like this :

I was updating my iPad to the latest  iOS version and the install crashed. whenever I’m trying to reset the iPad I get a message from after it extracted the firmware that the iPad couldn’t be restored and that an unknown error occurred (3503). Any clue ? ( Source: Apple Forum Discussion )

Sit back relax, There is solution for this problem.

Let me take you Step By Step so you would not be lost !!

How to Fix iTunes Error 5303 ( Installed Crashed or Stuck during Recovery Process )

Step-1 :Download IPSW files from below website you need to download correct file that relates to your Device model.

IPSW files are basically just individual firmware downloads for specific iOS devices. These files can be used to update iOS devices manually

Open >

Download the file related to your device model.

Step-2 :In this step you need download another software named U3Tools which you will be using instead of iTunes to Install or Restore your Apple Device.

Open >

Download from the above link and Install “3uTools” and Update to 2.16 or newer Version.

It is Important, make sure you update “3uTools” Manually after the installation. (Click on check for update at the bottom right corner)

Step-3 :Now open the 3uTools software and follow the below steps.

  • Once the 3uTools software is opened Connect your Device and close iTunes.
  • Click on “Flash & JB” Tab now Click on “EasyFlash” Options.
  • Browse then Select the IPSW File which you downloaded earlier from


You can see the above screenshot click on “Flash” it should work smooth.

Hopefully you will see your problem is solved.

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