This issue occurs when you are using Report Builder or Report Designer in BI Development Studio to change a dataset that is based on a SharePoint list data source configured for an authentication type other than Windows Authentication or Windows Claims Authentication. At this time a Web application that is using Claims Based Authentication with Forms Based Authentication (FBA) enabled is not supported.
The test connection button will work; however, the query designer will fail with an "Access Denied" error message.
The SharePoint list data extension from the client application supports only Windows credentials for impersonation; therefore, any SharePoint lists you want to directly build queries from must be in Web applications that support Windows authentication.
Craig Lussier edited Revision 2. Comment: added en-US to tags and title