A hidden bug in 3uTools causes it to timeout when automatically checking Apple’s firmware.json file for new devices. Disabling this feature forces a manual query.
Steps:
Ensure your computer's date and time are correct. Apple verifies SHSH blobs based on the current date and time. how to fix error unable to request shsh on 3utools when new
Confirm device connection & trust
Use official cable + direct USB port
Disable network blockers
Run as Administrator and retry
Check for Apple server reachability
Use alternative method / server (if applicable) A hidden bug in 3uTools causes it to
Collect logs if error persists