My problem was => The USB_Burning_Tool gives after 11% an error => [0x00301001]
Erase bootloader/Switch status/Enum device/Enum error
This was the solution for me, remember all data is gone after this ( factory reset)
1 Download the new software MK22PLUS_Android 7.1_170901.img or later
2 Rename file MK22PLUS_Android 7.1_170901.img to MK22PLUS_Android_7.1_170901.img
( replace the space into a underscore )
3 Download from internet Burn_Card_Maker_V2.0.3 or later
4 Start => Burn_Card_Maker (see screen shot )
5 Select the correct SD card ( minimal 2GB )
6 Formatting Yes (standard)
7 Open.. the renamed file
8 Make => SD card
9 Put the card into the player
10 Start powerup the player with the reset button pressed in ( 3..5 sec)
11 The player start to install android 7.1
Be aware that this action can lead to a defective player, of course yourself are responsible of this action