cant flash this D800


Hi

I got this Lg D800 in Boot Loop condition.

I downloaded the unique firmware file available on support, really big file.
and I am getting an error when flashing.

here logs.

info

Code:

Platform: LG Qualcomm
Selected port: COM93
Selected model: D800
Reading info...
Mode: Emergency
Initializing flash...OK
SW version: LGD800AT-00-V20y-310-410-AUG-05-2014+0
LAF Version: 1.0
Product ID: BS01S140109001911
IMEI: 013695-00-205161-5
Target operator: ATT
Hardware: rev_10


I can see it is version 2.0y and downloaded file is:
LGD800AT-01-V20c-310-410-FEB-02-2014+0.oct

Dont know if the following error is because of downgrade attempt…

Code:

--------------------------------------------------------------------------------
Checking data...OK
Platform: LG Qualcomm
Selected port: COM93
Selected model: D800
Reading info...
Model ID: LG-D800
IMEI: 013695-00-205161-5
Android version: 4.4.2
Battery level: 11%
Mode: Emergency
Initializing flash...OK
SW version: LGD800AT-00-V20y-310-410-AUG-05-2014+0
LAF Version: 1.0
Product ID: BS01S140109001911
IMEI: 013695-00-205161-5
Target operator: ATT
Hardware: rev_10
Opening "LGD800AT-01-V20c-310-410-FEB-02-2014+0.oct"...OK
Setting options...Failed!


any suggestion?