I was very hopeful that since SQL Server 2012 SQLCLR supports .NET 4.0 that SQL Server Reporting Services (SSRS) 2012 would support .NET 4.0 custom code assemblies. When attemp
Actually, I find that reports using .Net 4.0 assemblies will work fine in VS 2010 (PreviewProcessingService.exe)...
And the reports may also work for you when deploying them to SSRS 2012 SP1 in SharePoint 2013 integrated mode.
Here is the authoritative answer on when/where the .Net 4.0 CLR is supported by SSRS: http://support.microsoft.com/kb/2869522/en-us
For those of us who use SSRS in standalone mode (without SharePoint), we might be stuck on the .Net 2.0 CLR for a while.
I might be wrong and there might be more differences but having compared reports downloaded from reporting services and "identical" ones made in Visual Studio using .Net framework 4.0+ I think the only difference is that puts a ReportParametersLayout section in the xml. If you manually remove this from the xml version of the report file then upload hopefully it will work for you
SSRS 2014 is now released and custom code still does not support the .Net 4.0 Framework.
See prerequisites in the "Hardware and Software Requirements for Installing SQL Server 2014" (http://msdn.microsoft.com/en-us/library/ms143506(v=sql.120).aspx)
It's very amusing that SQL Server 2014 has just RTM'ed a few days ago and is already considered a "legacy application" by the .Net Framework guys who say:
.NET Framework 3.5 is not included by default in Windows 8 or Windows Server 2012, but you can download and deploy it for legacy application compatibility.
... see "Microsoft .NET Framework 3.5 Deployment Considerations" (http://technet.microsoft.com/en-us/library/dn482066.aspx)
I think the bigger issue is whether the support lifecycle of .Net 3.5 SP1 can actually be tied to the OS'es for which it was a default component. Whatever they say, I can't see Microsoft quitting support on .Net 3.5 as long as SQL Server continues making it a prerequisite in a product they are releasing today. The .Net Framework guys can't be too happy with the lazy SQL guys right now...