Many people must bear the inconvenient situation for dealing this pain in the back error, but thank God there is solution to fix the iTunes error 3194. So you don't have to bring your iPhone to the nearest Apple service.
Before we dig into the "how to fix" section, it's better to learn the causes that provoke iTunes error 3194 to happen. Below are the three common causes that yield iTunes error 3194.
Causes of iTunes error 3194
First cause. When trying to manually upgrade your iOS version using iTunes. Let's say you are using iOS 5.1.1 and decide to upgrade to newer version, for example iOS 6.1 but you don't know that Apple has stopped signing the version because the company has released another newer version, for example iOS 6.1.2. When you download the iPSW file of iOS 6.1 to upgrade via iTunes you get the iTunes error 3194. To short the story, this error is triggered if you try to upgrade to the already unsigned iOS version.
Second cause. If you try to downgrade your iOS in iPhone or iPad to the older version or back to the previous version. This could trigger the error. Since it's the Apple absolute rule that you can't go back to the lower iOS version once you're on the newer version. So if you want to avoid this error when downgrading your iOS, we suggest you to use SHSH blobs of the older iOS. Redsn0w is created to deal with downgrading problem. Use it.
Third cause. Perhaps you are restoring to the same iOS version you are using. Well this mistake can cause the iTunes error too. Thus make sure you firstly check the version you are about to get.
Additional; could be your iTunes version should be upgraded if it's too obsolete will effect to technical performance.
After you've understood the culprits of the problem now it's time to fix it.
How to fix iTunes error 3194 while downgrading or upgrading iOS version
By editing the Host.
Step 1. Close your iTunes if it's running.
Step 2. Now find file Host on your PC in this location.
For Mac OS /etc/hostsStep 3. Open file Host using Notepad, edit the file by adding the following text.
For Windows OS c:\windows\system32\drivers\etc\hosts
22.214.171.124 gs.apple.comhow to enter DFU mode here. And then upgreade / restore your iPhone.
Step 5. Once you've finished upgrading your device, then you need to remove this 126.96.36.199 gs.apple.com in file Host.
The shorter guides to fix iTunes error 3194
This is shorter tricks you can follow if the above solutions are too much for you. Let's do it.
1). Put your iPhone into DFU mode before you connect it to iTunes (in your device's screen you should see a usb wire with iTunes connected).
2). Once your iPhone connected to iTunes, then perform the update or restore again.
If the error still occurs, then you can ask me the solutions. Until then this is the solution I can offer to fix iTunes error 3194 on iPhone or iPad while downgrading / upgrading iOS version via iTunes.