QUESTION:  
I deleted devices in process device network view. Why do I still get the error message, "There is no authorization for the configuration of more than X devices..."?

ANSWER:  
The devices deleted from the network view are still in the process device plant view. The deletion from network view merely means that the assignment of the device to this network was removed. The device can then be assigned to another network. To completely remove the device, also delete the devices from the process device plant view.