| Cause Category | Specific Reason | |----------------|----------------| | | Faulty cable, non-USB 3.0 port, unstable power delivery, hub interference. | | Driver Conflict | Apple Mobile Device Driver missing, outdated, or overridden by 3uTools’ custom driver. | | Firmware/Baseband Mismatch | Attempting to flash an incompatible iOS version (e.g., downgrade without blobs). | | NAND/Flash Memory Issue | Bad blocks on device storage causing signature verification failure. | | Security Mechanisms | SEP (Secure Enclave Processor) mismatch or missing restore ticket. | | 3uTools Bug | Known bug in v2.56–2.60 where link 75 appears on A12+ devices in recovery mode. |