This is on a 2012 MacBook Pro.
I followed what I think is the normal process - Installed windows 10 and then elementary choosing to install side by side.
Elementary boots up fine, but when selecting windows in grub it just goes to a black screen instantly. I have left it for a couple of hours just incase there was something going on in the background but no luck.
I have tried Ubuntu 'boot-repair', and booting from a Windows USB key but none of the boot repair methods worked.
I think that both installs are installed with EFI boot if that makes a difference (although I'm not entirely sure what that means)
Any help would be appreciated.