There is no single reason for this error. It is a symptom of a broken communication chain. Let’s categorize the causes:
The -D (descriptor override) flag forces the tool to ignore some security checks. Use cautiously. fdl2 failed
The error is terrifying, but rarely a death sentence. In over 80% of cases, it is a software configuration issue—wrong drivers, wrong programmer, or a corrupted download. In 15% of cases, it indicates hardware degradation of the eMMC/UFS. Only in 5% of cases is the SoC or RAM physically dead. There is no single reason for this error