UEFI Boot Mode Ubuntu 12.04 and Windows 8.1 UEFI

I installed Ubuntu 12.04.5 on laptop (lenovo g4070 59417454) with existing Windows 8.1. But when I select Windows 8.1 in grub menu:

error: unknown command 'drivemap'
error: invalid EFI file path.

BIOS:

Boot Mode: UEFI
EFI:
ubuntu (WDC WD5000LPCX-24C6HTO)
Windows Boot Manager
ubuntu (WDC WD5000LPCX-24C6HTO)

No idea why I got 2 ubuntu options. Maybe after I used Boot Repair.

Using 2nd EFI option (Windows Boot Manager), it will successfully boot to Windows 8.1.

Using 3rd option, it will go to grub prompt.

UEFI Test:

cat /etc/fstab
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
#                
proc            /proc           proc    nodev,noexec,nosuid 0       0
# / was on /dev/sda11 during installation
UUID=a83b92ee-6243-4fd8-9008-17c05ef8715e /               ext4    errors=remount-ro 0       1
# /boot/efi was on /dev/sda2 during installation
#UUID=C0A6-125C  /boot/efi       vfat    defaults        0       1
# /home was on /dev/sda10 during installation
UUID=bb008f49-2160-43d6-9ee2-84023072b571 /home           ext4    defaults        0       2
# swap was on /dev/sda9 during installation
UUID=d7de343e-1cad-446a-b7ba-355414132816 none            swap    sw              0       0
UUID=C0A6-125C  /boot/efi   vfat    defaults    0   1

UEFI Test:

[ -d /sys/firmware/efi ] && echo "EFI boot on HDD" || echo "Legacy boot on HDD"
EFI boot on HDD

Kernel:

uname -r
3.16.0-031600-generic

Boot Repair Log:

paste.ubuntu.com/10532939

Add this to 40_custom.

gksudo gedit /etc/grub.d/40_custom
sudo update-grub
menuentry "Windows 8 UEFI" {
 insmod part_gpt
 insmod fat
 insmod search_fs_uuid
 insmod chain
 set root='(hd0,gpt2)'
 search --fs-uuid --no-floppy --set=root C0A6-125C
  chainloader (${root})/efi/Microsoft/Boot/bootmgfw.efi
}