I run into this weird issue with 8.1.42 where I have an instance that for some unknown reason does not have system.dataset.exportCSV available from the script consol and another one that has it.
I restarted the designer and the whole server but nothing have helped.
The thing about all these functions is that they all end up showing some kind of GUI dialog to do whatever they do, and this only makes sense in the context of a running Vision Client (or Designer).