When calendar objects have been exported via command uniexp into a XML file, it is important to keep in mind that before the objects are imported into a new node the Calculator engine have to be stopped. To do so:
From UVC console :
Go to Admin tab -> Nodes then from the Nodes List select
Now the uniimp command can be executed as per syntax described in DUAS documentation.
Once the objects are imported in the new node you can start the Calculator engine following the same procedure and selecting Start option instead.