The "Unable to request SHSH" error in 3uTools typically occurs when the software cannot verify the digital signature (SHSH blob) required by Apple's servers to flash or restore a specific iOS version. Common Fixes

Older versions of 3uTools may use outdated server addresses or protocols that Apple has since changed. Open 3uTools on your PC.

Right-click 3uTools icon → "Run as administrator" . Mac: Open Terminal → sudo /Applications/3uTools.app/Contents/MacOS/3uTools

Do not worry. In this guide, we will dissect exactly why this error occurs when dealing with new hardware or software, and provide to fix it permanently.