Currently, the stable version is or higher (as of 2025). Anything below v2.60 is likely to fail.
When you use 3uTools to restore or update an iPhone (especially using the "iTunes Flash" or "Pro Flash" mode), the software tries to communicate with Apple’s servers to request a signature for the firmware you are installing. how to fix error unable to request shsh on 3utools when upd
The error on 3uTools is rarely a death sentence for your device. In most cases, it is a simple network configuration issue—either your DNS is failing, your firewall is blocking the request, or you are trying to flash an iOS version that Apple no longer signs. Currently, the stable version is or higher (as of 2025)