virus remove option bug

i am using merapi new verson 1.4.3
Analysis of USB port,Please insert phone USB cable.
Connecting…
CPU TYPE:MT6571
Hardware version:CA00
Software version:0000
SecCfgVal :0x00000000
BromVersion :0xFF
BLVersion :0x01
Boot downloading complete!
FlashID:002C00BC00900055
Flash Type: NAND_MT29C4G48MAZAPAKD
FlashLen:20000000

>>Not support Nand flash.