I’ve had the fun task of shoe-horning some 2010 PSI projects into Project Server 2013 recently, and the good news is that as promised the PSI is still there just as we remember it!
One particular exception I kept seeing in my code immediately when using SharePoint Permissions Mode (ie a Default install) was the following:
Exception: Unhandled Communication Fault occurred
Which came with the unusually helpful accompanying ULS log errors;
06/11/2013 10:05:54.39 w3wp.exe 0x161C) 0x29B0 Project Server General ab3be Monitorable Unhandled exception in the process of routing the request to the app server: Target=https://host/PWA/_vti_bin/PSI/ProjectServer.svc, exception=[InvalidOperationException] Operation is not valid due to the current state of the object., StackTrace= at Microsoft.Office.Project.Server.WcfTrustedFacadeHelperMethods.
TryGetImpersonationContextInfo(String originalTargetUrl, OperationContext context, ImpersonationHeader& impersonationHeader) …
06/11/2013 10:05:54.39 w3wp.exe (0x161C) 0x29B0 Project Server Security aibp8 High Impersonation is not supported in SharePoint permission mode
The second log is the giveaway, I won’t be forgetting that limitation again!