The following features are not supported by Excel Services and may not display or may display only partially: Comments, Shapes, or other objects
This error occurs when you add Slicers to a PowerPivot workbook from a PowerPivot Field List.
PowerPivot for SharePoint
SQL Server 2008 R2, SQL Server 2012, SQL Server 2014
Excel Web Access cannot render the Shape object used to control positioning and formatting of Slicers added to a workbook from the PowerPivot Field List.
The following features are not supported by Excel Services and may not display or may display only partially:
Comments, Shapes, or other objects
Some features, such as external data queries, display cached data which can only be refreshed in Microsoft Excel.
Excel Web Access shows this error when you open a PowerPivot workbook in a browser and you click the Details button for the message, Unsupported Features This workbook may not display as intended.
This error occurs because the PowerPivot workbook contains Slicers whose layout is controlled by a hidden Shape object in Excel. The Shape object controls the formatting and positioning of the Slicers in horizontal and vertical placements.
Excel Services cannot render a Shape object, but because the object is hidden, the fact that it does not render is not an issue.
This error can be ignored. Click OK to close the error message and proceed to use the workbook and Slicers with no problem.