I've had this on mine a couple of times on my Focus hatch
The only way i got it open was to push the bootlid up and down, really hard, while pressing the release buttons on the boot
It's so intermittent i can't understand why it happens.
bet it aint the full loom,my thought like a lot of modern fords is the wires in the rubber boot at the top of the hatch where the wires are bl00dy tight and snap,very common problem on the galaxys,and a very cheap fix where you can rejoin and solder the wires back together for a lot less then 180 euros.
I've had this on mine a couple of times on my Focus hatch
The only way i got it open was to push the bootlid up and down, really hard, while pressing the release buttons on the boot
It's so intermittent i can't understand why it happens.
Just had this on my wifes 07 plate focus ghia. The lock was clicking when trying to open boot (by handle or key fob), so trying to work but not releasing. Found this link and tried pushing down on boot whilst using handle, and hey presto it worked.