Slicers cannot be created for offline OLAP PivotTables. To create a slicer for this PivotTable, you must change the PivotTable ...

Slicers cannot be created for offline OLAP PivotTables. To create a slicer for this PivotTable, you must change the PivotTable data source to be on-line OLAP. On the Options tab, in the Tools group, in the OLAP tools menu, click Offline OLAP and select On-line OLAP in the Offline OLAP Settings dialog box.