This slicer is already connected to another PivotTable which has grouped fields, or this PivotTable has grouped fields and ...

This slicer is already connected to another PivotTable which has grouped fields, or this PivotTable has grouped fields and the slicer is already connected to another PivotTable. Slicers can only be connected to a single PivotTable when it has grouped fields and is based on an OLAP data source.