1.The Adapter card into the computer's solid-state hard disk socket insertion is not in place, you can use a little force. 2.The hard disk is used incorrectly. Some will install M2NGFF hard disk based on 5ATA protocol, so it will not work. 3.The installation disk of the system must be 10.13,6 version or higher. 4.The partition format of hard disk is not correct. It is not recognized when installing the system. It must be GPT (GUID) partition format. Be careful not to use any partitioning software to partition the hard disk into PE system, otherwise it will bring numbness to the later installation work. 5.Do not install the system from , nor try to restore the system with your original backup, because the old and new versions of the for system disk format is not the same. Product Master Control: No Product Interface: M.2 NVME KEY-M Support system: For 10.5 or more This adapter card and hard disk can replace the original hard disk of the following type of notebook computer. For Pro retina A1398 A1502 2013 version (ME864 ME865 ME866 ME293 ME294) For Pro retina A1502 A1398 2014 version (MG 72 MGX82 MGX92 MGXA2 MGXC2) For Pro retina A1502 A1398 2015 version (MF839 MF840 MF841 MJLU2 MJLT2 MJLQ2) For A1465 A1466 2013-2014 version (MD711 MD712 MD760 MD761) For A1465 A1466 2015 version (MJVM2 MJVP2 MJVE2 MJVG2 MMGF2 MMGG2) For A1466 2017 version (MQD32MQD42MQD52, Model A1466EMC3178) colour: green Material: PC+metal Package Contents: 10 x Adapter Card Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.