The firmware is supported; the issue is on your computer or network.
You can prevent this error and protect your ability to manage your device's iOS version by following these steps:
Use a USB port directly on the motherboard (on the back of a PC) rather than a front-panel port or hub. 3utools Error Unable To Request Shsh
Look for any lines containing apple.com or ://apple.com (e.g., 74.208.10.249 ://apple.com ).
3uTools cannot connect to the server to verify the signature. The firmware is supported; the issue is on
Apple checks your device's unique ID (ECID) and the firmware version you want to install.
If 3uTools fails to fetch, use ( blobsaver on GitHub). This tool pulls the ECID and AppNonce directly from the device and saves the blobs before Apple closes the signing window. 3uTools cannot connect to the server to verify the signature
If 3uTools continues to fail, you can bypass it entirely by manually saving SHSH blobs using a different tool.
Before modifying any software settings, confirm that the firmware version you are trying to flash is still actively signed by Apple. Visit an official tracking site like . Select your specific device model. Look for your target iOS version.
You are trying to flash an older iOS version that Apple has stopped signing.