void Flash_EnableReadProtection(void){    FLASH_OBProgramInitTypeDef OBInit;    __HAL_FLASH_PREFETCH_BUFFER_DISABLE();    HAL_FLASHEx_OBGetConfig(&OBInit);    if(OBInit.RDPLevel == OB_RDP_LEVEL_0)    {        OBInit.OptionType = OPTIONBYTE_RDP;      ...

Well, if you have the option bytes set to RDP Level 2, it's a one-way street and no one can can do anything about it. You will find more details in RM0444, e.g. section 3.5.1.​Thank you for your reply.I have had the option bytes set to RDP Level 1,af...