Changes to PowerPivot Gallery and Snapshots in SharePoint 2016

The PowerPivot Gallery has had some functionality and supportability changes between SharePoint 2013/2010 and SharePoint 2016. This is due to the fact that Excel Services functionality has moved to Office Online Server. While the basic premise of the gallery remains the same and some of the same rules apply, there are some changes that you should be aware of that will require your attention while troubleshooting or configuring a new farm. This article is purely informative and is not meant to include any troubleshooting steps. We will publish more information on a case-by-case basis for relevant issues.

What is new?

1. Gallery Snapshots no-longer support PowerView in any form (this includes Power View reports imbedded in Excel/PowerPivot workbooks AND .RDLX files built from PowerPivot data models stored in the gallery). Here is an example of what you will see if you load a workbook with Power View sheets included:
   
   • The event receiver that detects the file upload has been modified to accommodate for this. When it detects an XLSX file, it flags “false” and when it detects anything else, it flags true per the below ULS entry examples:
     
     • We recommend loading your RDLX files into a regular document library to avoid any confusion with users.
     • Also, we recommend publishing PowerPivot workbooks with PowerView sheets to PowerPivot galleries by sheet to avoid snapshots being taken of the erroneous sheets (see the following blog for this “workaround”).
       • https://blogs.technet.microsoft.com/excel_services__powerpivot_for_sharepoint_support_blog/2014/08/14/power-view-sheet-causes-thumbnail-error-in-powerpivot-gallery/
2. You will now see charts and sheets have separate snapshots in the snapshot ribbon, for instance a sheet with multiple charts will be shown, then each chart will have its own snapshot preview.
   
3. Gallery Snapshots are now handled by Office Online Server. The old gallerysnapshot.exe and getsnapshot.exe processes that used to take the snapshots no longer exist. Office Online Server utilizes the Excel REST API to render and load the snapshots to the documents when they are uploaded to the library or modified. Also, it is done in the context of the user that performs the action rather than a service account.
   • For administrators: You will find log entries for these actions on the SharePoint Web Front End and Office Online Server ULS logs during the upload or update of the PowerPivot file in question.
     • If a VALID .xlsx document is uploaded, you will see an entry similar to the following ULS entry as the first call to the “ExcelRest.aspx” as the users login:
       • Name=Request (GET:http://<SITEURL>/_vti_bin/ExcelRest.aspx/<LIBRARY>/<DOCUMENT>.xlsx/model/Sheets
4. Because Gallery Snapshots are now taken in the context of the user that performs the update action to the document, it is a REQUIREMENT that the SharePoint User Profile Service and User Profile Sync is running and fully functional. It also must be associated with the web application of which the PowerPivot Gallery is hosted in.
5. It also requires that the Claims to Windows Token Services be running on your SharePoint Web Front End servers, but if you are in MinRole configuration, this should be running anyway.

What is the same?

1. The gallery continues to only have full support for PowerPivot documents.
2. The same classic views are still included with the gallery.
3. The PowerPivot Gallery (and all supporting features) are still only supported with Windows Authentication (SAML and Anonymous are not supported under ANY circumstances).
4. You can still add BISM content types and create Power View reports from PowerPivot data models and BISM connections directly from the PowerPivot Gallery GUI.
5. The Scheduled Data Refresh interface remains the same and you access and interact with it the same way as in SharePoint 2010 and 2013 via the PowerPivot Gallery.

This article is specific to PowerPivot in SharePoint 2016 On-Premise with Office Online Server. If you are looking for information on Gallery Snapshots for SharePoint 2013 or SharePoint 2010 with PowerPivot, please see our other blog posts on this subject:

• https://blogs.technet.microsoft.com/excel_services__powerpivot_for_sharepoint_support_blog/2012/12/27/powerpivot-for-sharepoint-gallery-thumbnails-not-rendering/
• https://blogs.technet.microsoft.com/excel_services__powerpivot_for_sharepoint_support_blog/2012/12/06/troubleshooting-the-powerpivot-gallery-thumbnails-not-rendering-invoking-and-analyzing-the-getsnapshot-exegallerysnapshot-exe/
• https://blogs.technet.microsoft.com/excel_services__powerpivot_for_sharepoint_support_blog/2015/03/25/with-powerpivot-2012-for-sharepoint-2013-thumbnails-may-not-always-generate-properly-in-the-powerpivot-gallery-for-non-powerpivot-workbooks-red-x/