Hi Thomas,
Same happening to me (SP10 system and studio).
Studio is dumping a null pointer exception stack trace when I try to do that:
java.lang.NullPointerException: while trying to invoke the method com.sap.ndb.studio.model.data.type.PrimitiveType.getName() of a null object returned from com.sap.ndb.studio.model.data.type.PrimitiveType.get(java.lang.String)
at com.sap.ndb.studio.view.ui.nodes.actions.CreateCalculatedColumn$1.doExecute(CreateCalculatedColumn.java:107)
at org.eclipse.emf.transaction.RecordingCommand.execute(RecordingCommand.java:135)
...
So this seems to be a HANA Studio bug. Could you please open an SAP incident for that (component HAN-STD-DEV)?
Thanks,
Lucas de Oliveira