The bottom door panels were badly rotted underneath the paint. The rot extended into the architrave.
Rot in bottom of all exterior french doors had gone through to the interior. This is very common and always occurs because the moldings allow water to get in if it has not been kept water tight or sheltered by an awning
The rot had extended into the architrave. This is not so evident in the photo as the paint is covering it up. Once a bit of pressure was applied the paint gave way and exposed the wood rot
The door has been repaired by replacing the wood below the glass
The repaired interior of the door just needs new latches now