Fix Redsn0w Unexpected Error 2601 While Downgrading iOS 6.0 to iOS 5.1.1/5.0.1/5.1
iPhone Dev Team had recently released an updated version of Redsn0w, Redsn0w 0.9.15b2. This version of Redsn0w not only lets you to tethered jailbreak iOS 6 but also offers downgrade option for those having SHSH blobs for iOS 5.x and 4.x. With Redsn0w 0.9.15b2 you can now downgrade iPhone 3GS/iPhone 4/iPod Touch 4G and iPad 2 from iOS 6.0 to iOS 5.x or iOS 5.x to iOS 5.x.
Those who are new to this might not be aware that, after every new firmware release Apple stops signing last firmware there by preventing users from downgrading iOS firmware. However, if you managed to save SHSH blobs for the firmware which Apple currently signing then you can downgrade device firmware using this blobs.
Unfortunately with iOS 5.0 Apple changed this method of firmware singing and you can no longer have any way to downgrade the firmware. But thanks to typical bug/vulnerability in all iOS 5.x firmwares , iPhone dev team managed to get the working method to downgrade firmware to iOS 5.x.
This will help to all users who have accidentally upgraded to iOS 6.0 and want to downgrade back to iOS 5.x also to those who want untethered jailbreak back. As iOS 6.0 is tethered jailbreak only and it will take some time for untethered jailbreak release.
We have posted complete step by step guide on how to downgrade iOS 6.0 to ioS 5.x along with video tutorial. During this downgrade process we encountered very annoying error whos solution is not yet available.
When you attempt to downgrade iPhone 4 from iOS 6.0 to iOS 5.x you might get an unexpected error 2601, couldn’t restore in Redsn0w and entire restore/downgrade process fails with your iPhone 4 stuck on firmware update screen.
If you also facing similar issue then here the way to fix unexpected error (2601). All you need to do is select “NO” when Redsn0w asks you to prevent baseband update. This is only for iOS 6.0 to iOS 5.x firmware downgrade.
That’s it, this should fix the error and you should be able to downgrade successfully. In order to remove from software update screen, simply follow DFU mode instructions and use TinyUmbrella or Redsn0w fix recovery mode option. If your iPhone 4 doesn’t boot then after DFU mode use iTunes and restore iOS 6.0 again and then proceed for downgrade process.