One or more of the fields in this PivotTable corresponding to the slicers chosen have "Include new items in manual filter" ...

One or more of the fields in this PivotTable corresponding to the slicers chosen have "Include new items in manual filter" selected. Slicers can only be used with fields where "Include new items in manual filter" is not selected. Click OK to unselect "Include new items in manual filter" for this field and connect the slicers.