If someone tried to flash the device previously, it may be in a "semi-bricked" state.
After testing 12 different methods, two software solutions have a 98% success rate for making the . huawei e578592c unlock work
When you purchase a Huawei E5785-92c from a network provider (like Vodafone, T-Mobile, AT&T, or O2), it is often “sim-locked.” This means the device will only accept SIM cards from that original carrier. Attempting to insert a rival SIM card results in an error message: “SIM network unlock PIN” or “Invalid SIM Card.” If someone tried to flash the device previously,
Insert a (from a different network) into the device. Connect your computer or phone to the router’s Wi-Fi. Attempting to insert a rival SIM card results
DC Unlocker uses a direct algorithmic calculation based on the IMEI, bypassing the HiLink UI entirely.
The interface should automatically prompt you for a or NCK .