Update: If you’re facing error 1 while downgrading from iOS 5, check the latter part of the post.
I recently updated to iOS 4.3.4 to test GEVEY Sim on my iPhone 4. Good news is that GEVEY Sim works fine, but I had a hard time coming back to iOS 4.3.3.
I was facing Error 1 in iTunes even though my device was in Pwned DFU Mode. Most of the sites on Google Search for this problem say that your iPhone must be in a DFU Mode. But, my iPhone 4 was already in DFU mode. Inspite of that, I was facing error 1.
Luckily, I came across JailbreakMovies which has an article telling how to downgrade iOS 5 beta to iOS 4.3.3. It explains the fix for Error 1.
How To Fix Error 1 in iTunes?
I assume that you tried to restore to iOS 4.3.3 from iOS 4.3.4 using saved SHSH blobs. And after about 3/4th restore was complete, you got error 1 in iTunes & the following screen on your iPhone:
To fix the error, follow these steps:
2. Open redsn0w and point it to iOS 4.3.3 IPSW. After redsn0w identifies IPSW file, click Next
3. You’ll be prompted to put your iPhone into Pwned DFU Mode. Follow the instructions on the screen and your iPhone will be in Pwned DFU Mode
4. Jailbreaking process will start on your iPhone once it is in DFU mode
5. After a couple of minutes the jailbreaking process will reach Installing Activation Bundles. Here, your iPhone will be frozen. Wait for a couple of minutes and then you’ll have to reboot by pressing Home + Power buttons
6. After rebooting, your iPhone will again show Connect to iTunes screen. Use TinyUmbrella to kick your device out of recovery
7. Once your iPhone restarts again, it’ll boot normally and it’ll be already jailbroken. You can then activate through iTunes
How To Fix Error 1 while Downgrading from iOS 5?
2. Launch Redsn0w and select “Extras”
3. Now select “Recovery Fix”
4. Now your device will be kicked out of recovery and error 1 will be fixed. Your iDevice will now be running iOS 4.3.3/4.3.5. You can then jailbreak iOS 4.3.5 using redsn0w or jailbreak iOS 4.3.3 using jailbreakme.com.
If you have any other queries, feel free to ask below!