V21 doesn't work, it kill cable, seller test v18 cable on v21 software, after this test can't run v18 software anymore. Crap.
Replied by Elyza on Sep 8, 2017
The V21 can work, but after use many times, it will made the device locked.
We recommend use V18 software!
That is when you received the package, use V18 software( never use V21 software from the beginning)
If firstly use V21 software, it will made the firmware update, then use V18 it will not work
Please be noticed.