d855 could not detect mode

need to flash g3. it stuck on lg logo.
i tried over emergency mode with p999 cable with 910k and normal usb cable
both do not work.
someone an idea?

Checking data…OK
Platform: LG Qualcomm
Selected port: COM31
Selected model: D855
Reading info…
Could not detect mode!
Performed by 2.2.6 software version.