If you have only one sheet on your dashboard, you just have to click on the sheet to get the data and crosstab options to appear again in Server. Is this the issue you are facing or are you trying to export data from multiple sheets simultaneously?
Thanks! It helped me, I was using one sheet for one dashboard, since I needed to provide filtering options for the user. One more question:
Is it possible to have only dashboards which provide option to download data? Because filtering in dashboard, then going to data sheet to download feels inconvenient..