Help with unlock verykool i129

Hi Sr I have one verykool and I need unlock and I try with pack 2 SPD TOOL
and display this error

Searching phone;
For an successful connection do the following:
1. Remove battery and usb cable
2. Insert the usb cable in the phone
3. Keep pressed the boot key and insert the battery
Phone detected (@oem66.inf,%dvcdsc%;SCI USB2Serial)
Preparing to sync;
Port opened [COM19];
Mobile type: SPRD3
FDL sent;
ERROR: Sync failed;

please I need your help, thank you