If it has a , Apple is no longer generating SHSH blobs for it. You must select a signed iOS version to bypass the error. 3. Repair Apple Device Drivers
根据 3uTools 官方开发团队的测试与排查，“Unable to request SHSH” 错误的常见原因主要有三类：
Use 3uTools to check which firmware versions are still signed (green) for your device in the "Flash & JB" > "Easy Flash" section 1.2.1.
The "Unable to Request SHSH" error occurs when 3uTools sends this request to Apple's servers, and the request fails. Based on research from 3uTools' own development team and community analysis, this error can almost always be attributed to one of four primary causes: i unable to request shsh 3utools fix install
. Faulty connection drivers can prevent SHSH requests from completing. Network Check
If 3uTools fails, you can use online services to generate the necessary signing information. Visit a trusted SHSH service site (like sh.host) 1.2.1. Copy your device's or EID from 3uTools.
Note for advanced users: Downgrading to an unsigned version is only possible if you previously saved local SHSH2 blobs for that exact device while that iOS version was still signed, and if a compatible SEP/Baseband firmware is available. 2. Clear and Reset Your Windows Hosts File If it has a , Apple is no
can help narrow down if the version you want is still signed by Apple.
If you have used jailbreak tools (like Checkra1n, Unc0ver) or modified iTunes in the past, your computer's "Hosts" file might be redirecting SHSH requests to Cydia/Saurik's servers instead of Apple's. 3uTools needs to talk to Apple to get the blobs.
The "Unable to request SHSH" error in 3uTools typically occurs at the 9% or 19% mark of a flash process Faulty connection drivers can prevent SHSH requests from
If 3uTools consistently fails despite your network being clear, external tools can bypass the software bottleneck.
打个比方：SHSH 就像一把独一无二的钥匙，你准备进入某个 iOS 版本的系统房间。苹果只在某个时间窗口内发放这把钥匙，窗口期一过就收回。你得在这之前自己备份一把，否则以后就无法再打开那扇门了。
Temporarily turn off Windows Defender, third-party antivirus software, and active VPNs. These frequently flag firmware signature requests as suspicious traffic.
Sometimes the default DNS fails to resolve Apple's server addresses.