I have successfully converted from a Tableau .twbx file to .twb and now have a .tde file for the data. How can this .tde be converted to either .csv or .xls(x) ?
From the Data menu starting in version 10.3, You can also export to CSV.
That command exports the entire data source, while the export commands on the worksheet menu export only the data referenced by the worksheet. Both are useful. One exports the entire data source, the other exports the fields used on the worksheet
There is a feature for Export to CSV from Version 10.2.2 . It is non-intuitive how to find it: select the Data | (data source name) | Export to CSV :