Excel Slicer Not Activating

I'm running Microsoft Excel for Mac version 15.33. I have a worksheet open and the Insert tab selected. Whether I select one cell, all cells, no cells, or just the cells in the row containing the column headers, the Slicer tool does not activate. I can't select the Slicer tool. 

Does anyone have a similar experience with the tool, or am I missing a step?

Thanks.