Microsoft .NET Framework 4.5 RC Readme

Date Published: May 31, 2012

For the latest version of the Readme click here.

1. .Net Framework Known Issues

1.1 .Net Framework Installation

1.1.1 The .NET Framework 4.5 RC language packs are not available on Windows 8 Release Preview

The .NET Framework 4.5 RC language packs cannot be installed on the Windows 8 Release Preview operating system, because the .NET Framework 4.5 RC is a component of the operating system. The .NET Framework 4.5 RC language packs can be installed on earlier supported versions of Windows.

To resolve this issue:

Download the language packs for the Windows 8 Release Preview operating system, or install a localized version of Windows 8 Release Preview to get the localized resources for .NET Framework 4.5 RC.

1.2 .Net Framework Uninstallation

There are no known issues.

1.3 .Net Framework Product Issues

1.3.1 General Issues

1.3.1.1 After the .NET Framework 4.5 is installed, the MSB3270 warning occurs in builds in Visual Studio 2010

Some project types in Visual Studio 2010 - for example, C++ projects - set the Platform property but don't set the PlatformTarget property. When PlatformTarget isn't set, MSBuild can't determine the project architeture - for example, x86. Instead, it assumes that the project target is Any CPU and throws architecture-mismatch warning MSB3270 even if the project and references are targeting the same architecture.

To resolve this issue:

-or-

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1.3.1.2 The .NET Framework 4.5 RC binary files cannot be redistributed

Per the Microsoft Software License Terms for the .NET Framework 4.5 RC, you may not redistribute the .NET Framework 4.5 RC binary files with your application.

To resolve this issue:

Your customers can download the .NET Framework 4.5 RC on supported operating systems from the .NET Framework Download Center. The .NET Framework 4.5 RC is included with the Windows 8 Release Preview and Windows Server 2012, so it doesn't have to be installed separately on those operating systems.

1.3.1.3 The Windows Runtime IRandomAccessStream interface reports invalid positions after reading past the end of the file

When you convert a Windows random access stream (IRandomAccessStream) to a managed stream, the managed stream uses a buffer by default. When the buffer is filled with the last bytes in the file, it reads past the end of the file, and the position is reported incorrectly. This issue affects any code that uses that position; for example, when you use the System.IO.Compression.ZipArchive class to read from a Windows Runtime stream.

 

Sample of where the problem happens:

       

   Windows.Storage.Pickers.FileOpenPicker fop = new Windows.Storage.Pickers.FileOpenPicker();

   fop.FileTypeFilter.Add(".zip");

  

   StorageFile file = await fop.PickSingleFileAsync();

   using (System.IO.Stream s = await file.OpenStreamForReadAsync())

   {

      using (var za = new System.IO.Compression.ZipArchive(s))

      {

         foreach (var entry in za.Entries) // Fails here....

         {

            // Do something here

         }

      }

   }

To resolve this issue:

Open the stream with a zero-length buffer. Instead of calling the file.OpenStreamForReadAsync() method, call file.OpenReadAsync(), and then call AsStreamForRead(0) on the resulting Windows Runtime stream.

 

For example:

   using (var ws = await file.OpenReadAsync())

   {

      using (var s = ws.AsStreamForRead(0))

      {

         using (var za = new System.IO.Compression.ZipArchive(s)) // This will now work correctly.

         {

            // Do something here

         }

      }

   }

1.3.2 ASP.NET

There are no known issues.

1.3.3 Winforms

There are no known issues.

1.3.4 Parallel Programming

1.3.4.1 TPL Dataflow has been removed from the .NET Framework 4.5 RC redistributable

The Task Parallel Library (TPL) Dataflow (System.Threading.Tasks.Dataflow.dll) has been removed from the .NET Framework 4.5 RC redistributable and is moving to an out-of-band shipping mechanism.

To resolve this issue:

To install System.Threading.Tasks.Dataflow.dll, open your project in Visual Studio 2012 RC, choose Manage NuGet Packages from the Project menu, and search online for the Microsoft.Tpl.Dataflow package.

 

 

1.3.5 Managed Extensibility Framework

1.3.5.1 MEF for Windows Metro style apps has been removed from the .NET Framework 4.5 RC redistributable

Managed Extensibility Framework (MEF) for Windows Metro style apps (System.ComponentModel.Composition.*.dll) has been removed from the .NET Framework 4.5 RC redistributable and is moving to an out-of-band shipping mechanism.

To resolve this issue:

To install System.ComponentModel.Composition.*.dll, open your project in Visual Studio 2012 RC, choose Manage NuGet Packages from the Project menu, and search online for the Microsoft.Composition package.

 

1.3.6 Entity Framework

There are no known issues.

1.3.7 LINQ to SQL

There are no known issues.

1.3.8 Windows Communication Foundation (WCF)

1.3.8.1 Default HTTPS protocol mapping causes issues

If you have a Windows Communication Foundation (WCF) version 4 service hosted in IIS, with both HTTP and HTTPS bindings enabled in IIS, the new default HTTPS endpoint feature in WCF 4.5 may cause issues in the following scenarios:

<protocolMapping><add scheme="http" binding="wsDualHttpBinding"/></protocolMapping>

When you upgrade to WCF 4.5, you may see the following error:

Contract requires Session, but Binding 'BasicHttpsBinding' doesn't support it or isn't configured properly to support it.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

 

This error occurs because the default HTTPS endpoint exposed for a WCF service with the new BasicHttpsBinding binding doesn't support duplex contracts.

A binding instance has already been associated to listen URI 'https://domain/address/service.svc'. If two endpoints want to share the same ListenUri, they must also share the same binding object instance. The two conflicting endpoints were either specified in AddServiceEndpoint() calls, in a config file, or a combination of AddServiceEndpoint() and config.

 

To resolve this issue:

To work around these issues, add <remove scheme="https" /> protocolMapping to the web.config file, or define an HTTP service endpoint explicitly within the service tag.

1.3.8.2 Error caused by IIS-hosted WCF services that use HTTP GET-enabled and non-HTTP endpoint

If your setup includes the following:

 

you may encounter the following error:

Exception: System.ServiceModel.ServiceActivationException: The service '/.../.../<serviceName>.svc' cannot be activated due to an exception during compilation. The exception message is: Security settings for this service require 'Anonymous' Authentication but it is not enabled for the IIS application that hosts this service.. ---> System.NotSupportedException: Security settings for this service require 'Anonymous' Authentication but it is not enabled for the IIS application that hosts this service.

To resolve this issue:

To work around this issue, enable anonymous authentication mode in IIS (at least for myservice.svc-Uri),  or create the HTTP GET metadata endpoint manually with ClientCredentialType==Windows/InheritedFromHost.

1.3.9 Windows Presentation Foundation (WPF)

There are no known issues.

1.3.10 Windows Workflow Foundation (WF)

1.3.10.1 Some of the new features in the Workflow Designer may cause issues with existing solutions

In the .NET Framework 4.5 RC, the Workflow Designer includes the following changes:

To resolve this issue:

Use the workaround for each issue discussed in the preceding list.

1.3.10.2 Host fails to start if you use workflows with the Workflow Identity parameter

The .NET Framework 4.5 RC includes a new workflow parameter, Workflow Identity, that is persisted to the SQL Workflow Instance Store. If you use workflows that include this parameter and its value is not null, you must update the Instance Store so it can store the value. Otherwise, the host will fail to start.

To resolve this issue:

Update the SQL Workflow Instance Store by running the script at the following location:

%windir%\Microsoft.NET\Framework\<version>\SQL\<language>\SqlWorkflowInstanceStoreSchemaUpgrade.sql

2. .Net Maintenance

2.1 Upgrading to Windows 8 Release Preview does not update .NET Framework 4 language packs

If you upgrade from the Windows 7 operating system to Windows 8 Release Preview, the .NET Framework 4 language packs that you previously installed on your computer are not removed or updated. This issue affects language packs that do not match the language of the upgraded Windows 8 Release Preview, not including English. For example, if you have an English edition of Windows 7 Ultimate and the .NET Framework 4 German language pack, and you upgrade your system to the English edition of Windows 8 Release Preview, the language pack will remain on your system but will not be updated to the .NET Framework 4.5 RC.

To resolve this issue:

Either uninstall the .NET Framework 4 language pack before you upgrade to Windows 8 Release Preview, or install the appropriate Windows 8 Release Preview language pack after you upgrade.

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