VirtualBox boots only in UEFI Interactive shell

I encountered the same problem and found that if I issue following command in the interactive shell, the virtual machine would boot into Ubuntu:

fs0:\efi\ubuntu\grubx64.efi

(Use backslash, forward slash does not work. Commands in UEFI interactive shell are case insensitive.)

My VirtualBox version is 4.3.20 r96997, Ubuntu version is 14.10 AMD64. I do not know why this happens and how to solve it. Just found this not elegant and still a little bit troublesome workaround.

Update 1:

I read this, tracked down to a bug report and found a better workaround.

Update 2:

Workaround in Update 1 failed. I turned off the virtual machine, launched it. And it booted into UEFI Interactive shell again. According to this, the problem was probably cause by a VirtualBox bug. I am still looking for further solution to this.

Update 3:

Finally found an solution. According to this, you need to create a startup.nsh script manually. Except for the method in mentioned post, you can also do this:

$ sudo mount /dev/sda1 /mnt
$ cd /mnt
$ sudo sh -c "echo '\EFI\ubuntu\grubx64.efi' > startup.nsh"

I had the same problem (with the EFI enabled because I couldn't get it to run otherwise). Strange; although installation of Ubuntu 14.04.2 got no error, installing Kubuntu 15.04 failed to finalize. It froze at the very end when asked to remove DVD. After reset, it booted fine but after power down it brought up shell.

So, to avoid shell type:

fs0:
edit startup.nsh

and on the opened window add these 2 lines:

FS0:
\EFI\ubuntu\grubx64.efi

press Ctrl + s and Enter to save and Ctrl + q to quit. Then restart VM.

Alternatively, you can always use these 2 lines to exit shell and boot OS. But second time you restart you will be in a shell again and to avoid it edit startup.nsh.

Another option is to un-check the Extended Features option called 'Enable EFI' under 'Motherboard' for your VM.

Had this issue come up for Gnome Ubuntu 12.04.2 amd64bit installation.

Discovered this after having to change settings for hardware acceleration. I was left with having VT-x/AMD-V, Nested Paging enabled. My VM has 2 CPUs, 8GB RAM for reference.

After un-checking the issue is completely by-passed Gnome Ubuntu boots up no issues. Running Virtual Box 4.3.18 r96516 on Windows 7 64-bit Host.