Don't let the errors trick you :)
Dual boot: Windows 8.1 and openSUSE 13.1.
After installation no boot loader - system boots into Windows
Selecting "Installation" - "Abort" - "Boot into installed system" allows to boot into the installed system, but that's an impractical situation.
The bootloader preselected at time of the installation is "grub". Trying to select "grub2-efi" and "enable secure boot" results in the following error:
"unsupported combination of hardware platform x86_64 and bootloader grub2-efi opensuse 13.1".
After the installation trying to mount the "EFI boot" partition (/dev/sda2 in my case) to install grub2 with: "grub2-install --target=x86_64-efi /boot/efi, the following error was printed:
"mount: unknown filesystem type 'vfat'".
After a lot of reading I finally realized I had changed the "Secure Boot" settings in the BIOS before.
Re-setting the BIOS "Secure Boot" back to "Enabled" and voila:
The installer automatically mounts the EFI boot partition with /boot/efi and the Boot Loader is already set to Grub2-EFI.
After the installation there are two entries in the boot menu: openSUSE 13.1 and Windows Boot Manager (on /dev/sda2).
selected "Security" in the BIOS top menu, then "Secure Boot Control" and changed that from "Disabled" to "Enabled". The "UEFI/Legacy Boot" was also changed back to "Both" System will boot by following UEFI/Legacy Boot Priority setting.
There's a really good How-To which I didn't follow entirely but it has helpful tips:
How to: Dual-boot (preinstalled) Windows 8 and Linux - UEFI etc.