Now that you know the potential causes, follow these troubleshooting steps in order. Start with the simplest solutions and work your way to the more advanced ones.
Sometimes "Easy Flash" fails because the device state is "Normal." Put your device into (the screen should be black). 3uTools will detect a device in DFU mode. Try the flash again. Check the "Hosts" File
Right-click the file named and open it with Notepad (Run as Administrator). Look for any lines containing apple.com or ://apple.com .
Download and install the latest build, then restart your PC. 2. Verify iOS Signing Status
Every time you restore or update an iPhone, iPad, or iPod touch, the device sends this signature request to Apple for verification. Apple’s servers compare the requested firmware version against its current "signing window." If the version is still being signed, a valid SHSH is issued and the process continues. If the version is older and no longer supported (closed by Apple), the request fails, leading directly to the "Unable to Request SHSH" error.