Hello,
I recently upgraded from SharePoint 2010 to 2013.
On this new server the PowerPivot Gallery reports are no longer working. The error says
"An error occurred while loading the model for the item or data source 'EntityDataSource'. Verify that the connection information is correct and that you have permissions to access the data source."
This is what I can see in the ULS Log:
"w3wp.exe (0x1AE4) 0x2F38 SharePoint Foundation Claims Authentication bz7l Medium SPSecurityContext: Could not retrieve a valid windows identity for username 'Domain\levente.rog' with UPN 'Levente.Rog@domain.local'. UPN is required when Kerberos constrained delegation is used. Exception: System.ServiceModel.FaultException`1[System.ServiceModel.ExceptionDetail]: WTS0003: The caller is not authorized to access the service. (Fault Detail is equal to An ExceptionDetail, likely created by IncludeExceptionDetailInFaults=true, whose value is: System.UnauthorizedAccessException: WTS0003: The caller is not authorized to access the service. at Microsoft.IdentityModel.WindowsTokenService.CallerSecurity.CheckCaller(WindowsIdentity callerIdentity) at Microsoft.IdentityModel.WindowsTokenService.S4UServiceContract.PerformLogon(Func`1 logonOperation, Int32 pid) at SyncInvo... 4346099c-2de5-80a3-b6fd-c52e095aeafe"
If I configure the report with a pre-defined user (@ Manage Data Sources -> EntityDataSource -> Stored Credentials) the reports work. So there must be some Claims/Kerberos setting the problem. I have read every post on this topic and theSQL BI Features Setup for SharePoint Guide but wasn't able yet to determine the issue.