| Cause Category | Specific Reason | |----------------|----------------| | | Wrong or outdated USB VCOM / Mediatek / Qualcomm drivers. | | USB/Port Issues | Unstable connection, bad cable, or USB 3.0 port incompatibility. | | Phone State | Battery too low, phone exiting Preloader/BROM mode too quickly. | | Tool Version | Outdated Unlock Tool that doesn’t support your device’s security patch. | | Authentication Error | Some tools require an active login or license for the DA to send. | | Anti-Virus/Firewall | Security software blocking the DA file as malware. | | Wrong Flash Mode | Using Download Agent meant for Qualcomm on a Mediatek chipset. |
Now, let’s fix it.
is a small piece of code sent by the servicing software to the device's internal RAM. Its job is to initialize the storage (EMMC or UFS), verify the device's security signatures, and prepare the hardware to receive new firmware or commands to bypass locks. When UnlockTool reports that it "failed" to send this agent, it means the device rejected the code or the connection was interrupted before the code could execute. Common Causes for the Failure unlock tool sending download agent failed