I think I have done a silly thing - re-locked the boot loader.
Now I can’t unlock it again to restore the recovery image.
Does anyone know how to force fastboot to unlock?
Does anybody know why re-locking the boot loader would do this?
Why did I re-lock the boot loader? Well, when I was booting into a custom image there was a message on the boot screen warning me that the boot loader was unlocked and I was wondering if that meant I should lock it again. So I did. It seems that it was a bad idea.