Modern MediaTek devices utilize Serial Link Authorization (SLA) and Download Agent Authentication (DAA) . Without bypassing these, the device will reject the flashing attempt.

The most frequent culprit is the driver. You should use a dedicated tool like to uninstall all existing MTK or VCOM drivers, then manually install the latest MediaTek Preloader/BROM drivers . For best results: Ensure Driver Signature Enforcement is disabled on Windows.

Request bypass for dimensity8100(mt6895) · Issue #86 - GitHub

The phone must be completely powered off. If the device is in "Preloader" mode instead of "BROM," the flash tool will fail to initialize the environment. How to Fix "BROM Protocol Error: Check Device Environment" 1. Correct Driver Installation