PoVEL A Use this code instead: FLASH_OBProgramInitTypeDef obInit;   /* Allow Access to option bytes sector */ HAL_FLASH_Unlock(); HAL_FLASH_OB_Unlock(); obInit.OptionType = OPTIONBYTE_RDP; obInit.WRPState  = OB_RDP_LEVEL_1; // VERY IMPORTANT !! DONT ...