Have you had a chance to create a dashboard using the Table widget from the DASH palette? If so, you've seen the message that appears after you've selected your dataset that says:
"No visualization attribute found for mapping to dataset columns."
Here's a quick screen shot
I've been getting a number of questions recently about this message. Even though you might interpret this as an error, this message does not indicate an error. I guess depending on how you read it, it may sound a bit scary, but let me see if I can explain.
Most widgets require you to configure something about the widget. For example, the analog gauge requires that you provide a value that the needle will display. If you didn't provide that value, the gauge would not know what to show. With the Table in the first release, there was nothing that was actually *required*. The table will simply show you all the columns in your dataset. So, instead of just leaving the required section blank, the thought was to put in a message that indicates there is nothing there. (Kind of like the old "This page intentionally left blank" for those of us that remember those days).
If you expand the 'Optional Settings' you should see some things that you can specify such as the title, or which columns should actually be displayed in the table.
Hope this helps!