: Apple only allows restores to "signed" firmware versions. If you are trying to downgrade to an older, unsigned version, it will fail unless you have saved SHSH blobs for that specific device previously.
When dealing with a bootlooped device, the standard flash may fail. One known workaround is to place the phone in Recovery Mode and try the following in 3uTools:
: Apple's verification servers or the 3uTools servers are experiencing temporary downtime. 3utools Error Unable To Request Shsh
Hello,
Are you trying to a disabled device?
Disclaimer: Modifying iOS firmware carries risks, including voiding warranties or bricking devices. Always back up your data before using 3uTools. This guide is for educational purposes.
This is the most frequent cause. Apple typically stops signing older iOS versions within weeks of a new release. If you are trying to flash a firmware version that Apple is no longer signing, the server will simply refuse to provide the SHSH blob, generating the error. You can check current signing status at websites like ipsw.me . : Apple only allows restores to "signed" firmware versions
If Apple has stopped signing a particular version of iOS, the request for an SHSH blob will fail. Causes of "Unable to Request SHSH" in 3uTools