Modifying the SharePoint v4.master page for the PowerPivot Gallery

Attempting to use a modified version of the SharePoint v4.master page is a great way to style our SharePoint site.  If you interested in doing this, then the first thing to do is to make sure that you go to the right place:

1. Go to Site Settings -> Site Collection Features -> Make sure “SharePoint Server Publishing Infrastructure” is activated.
2. Go to Site Settings -> Manage Site Features -> Make sure “SharePoint Server Publishing” is activated.
3. Finally then on the Site settings page, you should get an entry for Master Page under the “Look and feel” section.

Modifying the master page works fine for the landing page, document libraries, calendar and other pages—but causes an error with the PowerPivot Gallery.  The error is—“The referenced file ‘/_layouts/Gemini/ReportGalleryView.ascx’ is not allowed on this page."  The problem is that the page cannot load because the control ReportGalleryView.ascx is not marked as a safe control. To mark report galllery view as a safe control the following like should be added to web.config on "SafeControls" (under C:\inetpub\wwwroot\wss\VirtualDirectories\<web app port#, e.g. 80), in the <SharePoint>/<SafeControls> section

<SafeControl Src="~/_layouts/powerpivot/*" IncludeSubFolders="True" Safe="True" AllowRemoteDesigner="True" SafeAgainstScript="True" />

Enjoy.