The iTunes 3194 error (iPhone 3194 error) that you are experiencing is essentially the lack of communication between the program (iTunes) and Apple's update servers. Apple is currently checking the firmware of your iOS device to see if it is signed or unsigned. If the firmware is not trusted or "signed", you will experience this problem.
The usual cause of Error 3194 is that you have used outdated firmware in demotion or have jailbroken your iOS device that modifies the host file, especially the IP address of the server responsible for the updates. In most cases, Apple does not want its products to be jailbroken, so they generally do not offer complete solutions for this particular case. However, here at apple understand that this community is huge and that if you want to be "clean", we have these solutions ready.
The 3194 error often occurs when iTunes on your computer can not connect to the Apple Software Update Server. This is usually due to unsigned or expired firmware used during an iOS upgrade and restores, or a network connection problem on a computer. The first method you can use is to modify the hosts file on your computer to make sure that iTunes can communicate with Apple's update server. The following are specific steps.
STEP 1: Make sure iTunes is stopped on your computer (Windows / Mac).
STEP 2: Open the host files on your computer:
- For Windows PC: c:\windows\system32\drivers\etc\hosts
- For Mac: open Terminal, type this command and press Return: sudo nano /private/etc/hosts/etc/hosts
STEP 3 Open hosts file with administrator rights.
STEP 4: Copy "18.104.22.168 gs.apple.com" into the last line of the Hosts file.Then, "Save" the file.
STEP 5: Connect iPhone to PC via USB cable and open iTunes.
STEP 6: Put the iPhone / iPad / iPod in DFU mode by turning off the phone, then hold down the Home and Power buttons for 10 seconds, then release the Power button while holding down the Home button until iTunes informs you device is being recovered.
STEP 7: In recovery mode, you can restore the iPhone. Hoever, restore iPhone will erase all data from your iPhone, so make sure you always back up your iPhone with iTunes or iCloud.
STEP 8: Once your iOS update is complete, return to the hosts file and delete the "22.214.171.124 gs.apple.com" line again so that iTunes can update itself as usual. This is an essential step, otherwise you may encounter errors when updating or installing iOS versions.