Here is a step-by-step guide to resolving the most common causes.
：连接设备后，同时按住电源键和 Home 键（无 Home 键机型方法略有差异），约 10 秒后松开电源键，继续按住 Home 键约 5 秒，直到 3uTools 提示检测到设备处于 DFU 状态。
An outdated version of 3uTools may have trouble communicating with newer Apple servers or handling the latest device hardware.
utility instead. This often bypasses the 9% SHSH request hang. 4. Check Network and USB Connections A simple connection drop can interrupt the SHSH request.
Right-click the file named and open it using Notepad (with Administrator privileges). Scan for any lines containing apple.com or ://apple.com .
If you are stuck at 9% "Unable to request SHSH," follow this order of operations: Verify signed firmware via the ProFlash tab.
Sometimes, security software blocks 3uTools from sending the request to Apple’s servers.
When attempting to request SHSH blobs using 3uTools, users may encounter an error message or a situation where the tool fails to retrieve or save the necessary files. This issue can occur due to various reasons, including:
With the causes in mind, let's move on to the solutions. The following steps are organized from the simplest and most common fixes to more advanced workarounds.
The software tried to ask Apple’s servers (or a local SHSH cache) for a signature blob (( \textECID + \textfirmware version )) needed to restore iOS to a specific version. The request failed because:
Saving SHSH blobs is crucial for future downgrades or jailbreaks. If 3uTools fails to request SHSH, it is usually due to network connectivity, version mismatches, or Apple's server restrictions.
Temporarily turn off Windows Defender or third-party suites like Norton Antivirus or McAfee which frequently block raw outbound cryptographic requests. Flush the Windows DNS Cache: Press Windows Key + R , type cmd , and press Enter. Execute the command: ipconfig /flushdns
Use an original Apple lightning/USB-C cable. Try a different USB port on your computer, preferably one directly on the motherboard (back of the PC).
Before diving into the fixes, it is important to understand why 3uTools needs SHSH blobs.
DFU（Device Firmware Update）模式是比恢复模式更深层的刷写状态。将设备正确进入 DFU 模式后，3uTools 有时能够绕过部分 SHSH 验证流程。