Before doing anything, verify whether Apple is still signing the iOS version you want.
If unsigned: You cannot request SHSH from Apple. You must either:
3uTools uses its own certificate tunnels to talk to Apple. Apple updates its security certificates every few weeks. If you are using an older version of 3uTools (pre-v4.0), Apple may simply be ignoring your request because the encryption handshake is deprecated.
Update 3uTools: Ensure you are using the latest version of 3uTools as updates often include fixes for SHSH request errors. i unable to request shsh 3utools fix better
Check iOS Signing Status: Apple only allows restores to specific iOS versions. If the version you want to install is "unsigned," you cannot request SHSH for it unless you previously saved your own "SHSH blobs".
Repair Drivers: Use the Repair Driver utility in the 3uTools "Toolbox" tab to ensure your PC communicates correctly with your device.
Network Check: Disable any firewalls or VPNs that might be blocking the connection to Apple's signing servers. Detailed Solutions Before doing anything, verify whether Apple is still
Use DFU Mode: If "Easy Flash" fails, try putting your device into DFU Mode and attempt the flash again.
Check USB Connection: Use an original Apple lightning cable and a different USB port on your computer to rule out hardware communication issues.
Apple ID Binding: Some newer restore processes require you to bind your Apple ID within 3uTools to complete the signing request. If unsigned: You cannot request SHSH from Apple
Are you trying to upgrade to the latest iOS version, or are you attempting to downgrade to an older one? How to Fix 3uTools 9% ERROR Unable to request SHSH Latest
If all these fail, you need a better solution.
If 3uTools still fails, try:
If you have saved SHSH blobs for that unsigned version:
Note: This only works for 64-bit devices (iPhone 5s and later) and usually requires the device to be in DFU mode.