u7519 always error 21 what is the problem

[mariopaz222]

DC - Unlocker 2 Client 1.00.0540

Detecting card :

selection :
manufacturer - Huawei phones
model - Huawei U7510/U7517/U7519

Found Phone : 19
Model : Huawei U7510/U7517/U7519
IMEI : 356192032223039
Firmware : APP-U7519V100R001USAC85B638-20090925

================================================== =================

Unlocking, please wait ...

Preparing Boot Download mode ...

unlock failed !

(error code 21)

need help i buy the vygis actvation for unlock this phone and always error

[Vincentas]

Detect phone by autodetect. Check, if no other modems or phones are connected to computer at unlock time. Check, if you do not miss to reconnect usb cable when software ask for it.