: A faulty or third-party cable can cause data transmission errors. Use an original Apple Lightning or USB-C cable and try a different USB port on your computer.
Here’s a helpful, step-by-step guide to troubleshooting the “Unable to request SHSH” error in 3uTools when trying to upgrade or restore an iOS device. how to fix error unable to request shsh on 3utools when upd
Apple only allows you to install iOS versions that they are currently "signing". If you are trying to downgrade to an older version that Apple has "closed," you will consistently get the "Unable to request SHSH" error because Apple's servers refuse to provide the signature. : A faulty or third-party cable can cause