: This is the most common fix. Older versions of the software may have outdated server links. Visit the 3uTools official site to download and install the latest version. Check Signing Status
If the error happens immediately after clicking "Save SHSH," it is usually a network configuration issue. i unable to request shsh 3utools fix install
(official)
You can save SHSH blobs for iOS versions that Apple is currently signing. : This is the most common fix
: Apple only allows the installation of "signed" iOS versions. If you are trying to install an older, unsigned version, the SHSH request will fail because Apple's servers are no longer providing authorization. i unable to request shsh 3utools fix install