Hi, Im trying to move our Reporting Services files into the new BI Report Server Project in VS2010 / Data Tools 2012. This project type seems to work well - except that Im having problems using the deploy functionality for reports with references to external .Net assemblies. No matter how I try, deploy function results in errors even though I can manually upload my reports (using Report Manager web interface) and successfully execute them. Using a simple test report, containing nothing else than a textbox with the following expression: =TimeZoneInfo.ConvertTime(DateTime.Now, TimeZoneInfo.Local, TimeZoneInfo.FindSystemTimeZoneById("Central Standard Time")) and a reference to a version 3.5 System.Core dll (set in report properties->References) like this: System.Core, Version=3.5.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089 deploying this report results in an error The definition of the report '/Report1' is invalid.. Preview (using .Net 4) doesnt work as [BC30560] TimeZoneInfo is ambiguous in the namespace System. However, a manual upload via Report Manager yields no errors and works fine. If I Remove the reference to System.Core I get another deploy error The Value expression for the textrun Textbox1.Paragraphs[0].TextRuns[0] contains an error: [BC30451] Name 'TimeZoneInfo' is not declared which I guess makes sense since TimeZoneInfo is not part of .net 2.0 which seems to be used by the Report Server. But, removal of the this System.Core reference makes preview in SSRS work again. It seems like the deploy functionality if SSRS/Data Tools doesnt consider the external report references, but preview does. Has anyone worked around this? Id really like to use the deploy functionality. Also, using SQL Server 2012, is it not possible to have report server using a later CLR version than 2.0 for expressions and custom code? Microsoft Visual Studio 2010 Version 10.0.40219.1 SP1Rel SQL Server 2012 Microsoft SQL Server Data Tools 10.3.20225.0 Microsoft SQL Server Reporting Services Designers Version 11.0.2100.60 Thanks