When trying to edit a web part in the Business Intelligence site with SharePoint Designer, I got this error
This web site has been configured to disallow editing with SharePoint Designer.
To allow editing open this file on the SharePoint server C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\TEMPLATE\SiteTemplates\PWA\XML\ONET.XML and remove this part DisableWebDesignFeatures="wdfopensite" from the line <Project Title="Project Web App" Revision="2" ListDir="$Resources:core,lists_Folder;" SiteLogoUrl="/_layouts/inc/pwa/images/SiteIcon.png" xmlns:ows="Microsoft SharePoint" DisableWebDesignFeatures="wdfopensite" UIVersion="4">
Restart IIS and repeat for all other, if any, SharePoint Servers.