if you are talking about that little error in the bottom right of your computer screen that says something like usb failed to recognize with a yellow triangle, try rebooting that usually works for me if not
uninstall the lg driver
reboot then reinstall the lg driver and you should be good to go..
AT&T LG G2(Black)-SOLD
AT&T LG G-Flex-completely stock
"Its not the device....its operator error."