The rear door is not closing correctly, and is keeping the interior light on.
Hello. Assuming that the light control switch in the front is properly set, and you have followed the instructions in the owners manual, then the problem is likely the light switch in the door jam. This is a relatively common problem on Range Rovers, but is usually related to the main light control switch. Check to see if the door is shutting and locking normally, or does not close completely. If the door does not shut completely, the light switch will stay on. Several problems can cause the door not to close properly, including the lock mechanism being out of adjustment, or broken. The door latch on the door jam can also be out of adjustment, and can be moved to fully close the door. If these issues are still not solving the problem, then I would go to a qualified technician to inspect and repair your faulty door.