In view of the protection of users' privacy and data, and to better gel with Mi Cloud services to 'locate your device', the Redmi Note 3' bootloader is locked since last decemeber 2015. Following suite, with be Mi Note/Pro and Mi 4c, with immediate effect.
This is also inline and in response to security concerns laid down by Google. Hence, there is a change to the ROOT access in CN DEV ROM, and default SU (Super User) will be removed by default. However, if ROOT is required, you can still have it ROOT-ed but will require you to take extra steps.
If your bootloader will closed, you can not able to flash custom ROMs...only official stock MIUI. Èç¹ûÄãµÄÒýµ¼³ÌÐò½«¹Ø±Õ£¬ÄãÄܲ»Äܹ»ÉÁ×Ô¶¨Òå¹âÅÌ...ΨһµÄ¹Ù·½ÏÖ»õMIUI¡£
If you are now custom ROM, then everything is all right. You will be in trouble, when you install again official MIUI.
Èç¹ûÄãÏÖÔÚµÄ×Ô¶¨ÒåROM£¬È»ºóÍòÊ´󼪡£Äã»áÓöµ½Âé·³£¬µ±ÄãÔٴΰ²×°¹Ù·½MIUI¡£