The Visual Spreadsheet wizard asks that you add at least TWO columns of data before interacting with the browser. This is because Xena was designed to allow you to find correlations within the data and you need more than one type of data on the screen to find a trend.
Add another column of data and click Done. You can always delete this column after you have completed the wizard if it is not needed.
In general, we recognize genes from the HUGO gene name space. If you gene name isn't recognized, try looking at Gene Card and see if other names listed there are recognized.