Lg Flash Tool 2014 and %2 error topic

Hi all,
I have D802 International 16GB device and D802TR V20C stock rom installed.
In order to install Germany or Open Europe V20H firmware;
* I installed LG drivers : LGUnitedMobileDriver_S51MAN313AP22_ML_WHQL_Ver_3.1 3.2
* I downloaded V20H Kdz file and Lg Flash Tool 2014
* Switch to download mode

Everytime I stack on %2 of process and fail. I tried different combinations with different KDZ file but result is same.
I did not understand what is the problem. (win7 64 Enterprice)
Also I tried on another computer but result is same. (win7 x86 Ultimate)

Can anyone help me please?
Thanks.