(Tableau public) How to fix 'data preview unavailable' when connecting tables using joins. The preview pane has no 'update now' option.

Hi, @Andrew Thungu​ 

Since the join key between the data has not been set, an error occurs and the preview cannot be displayed. Can you specify an appropriate join key?

If you click on the exclamation mark between two data points, the join key specification screen will be displayed.

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