I can give you a specific for your exact device.
Ensure your Windows "hosts" file hasn't been modified to block Apple’s servers (often done by older jailbreak tools like TinyUmbrella). 4. Enter DFU Mode Manually i unable to request shsh 3utools fix install
An outdated version of 3uTools may have trouble communicating with newer Apple servers or handling the latest device hardware. I can give you a specific for your exact device
3uTools must connect to Apple’s TSS servers to request the SHSH blobs. If your connection is blocked, the request will time out. i unable to request shsh 3utools fix install
are digital signatures Apple uses to verify the firmware you are installing.
Click at the bottom right of the 3uTools window. Install any pending updates and restart the program. 3. Check Your Internet and Firewall Settings