Your Latitude laptop cannot be shut down or restarted at all when on docking station model Standard E-Port Replicator. It shuts down without the docking station though. The typical behavioral pattern is as follows: you start the laptop with a mounted E-Port Replicator after that unmount/undock, then mount the laptop back again and try to shut down or restart it.
Most probably you have a built in Webcam on the laptop’s display. Because of compatibility issues between the Dell’s Integrated Webcam driver and the E-Port Replicator a shutdown or restart of the Laptop is not possible.
This solution applies only to models Latitude E6400 or E4200 connected to a Standard E-Port Replicator!
Rollback of Dell’s driver to the Microsoft Generic Webcam driver:
In Device Manager (Gerätemanager) -> Imaging Devices (Bildbearbeitungsgeräte ) -> Integrated Webcam -> Properties (Eigenschaften)
-> Driver (Treiber) -> Rollback Driver (Installierter Treiber)
After this step the Driver Info should look like this and Laptop should shut down and restart normally