I've VS 2010 and recently installed WCF RIA Services V1.0. For testing I have created a new Silverligh Business project but now every now and then when I rebuild the solution I receive the following error:

Does anybody know why I get this?

Thanks

```
Error   1   The "CreateRiaClientFilesTask" task failed unexpectedly.
System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.ServiceModel.DomainServices.Tools, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.
File name: 'Microsoft.ServiceModel.DomainServices.Tools, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'
   at System.RuntimeTypeHandle.GetTypeByName(String name, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMarkHandle stackMark, Boolean loadTypeFromPartialName, ObjectHandleOnStack type)
   at System.RuntimeTypeHandle.GetTypeByName(String name, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark& stackMark, Boolean loadTypeFromPartialName)
   at System.RuntimeType.GetType(String typeName, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark& stackMark)
   at System.Type.GetType(String typeName, Boolean throwOnError)
   at System.Web.Hosting.HostingEnvironment.CreateWellKnownObjectInstance(String assemblyQualifiedName, Boolean failIfExists)
   at System.Web.Hosting.HostingEnvironment.CreateWellKnownObjectInstance(String assemblyQualifiedName, Boolean failIfExists)
   at System.Web.Hosting.ApplicationManager.CreateObjectInternal(String appId, Type type, IApplicationHost appHost, Boolean failIfExists, HostingEnvironmentParameters hostingParameters)
   at System.Web.Hosting.ApplicationManager.CreateObjectInternal(String appId, Type type, IApplicationHost appHost, Boolean failIfExists)
   at System.Web.Compilation.ClientBuildManager.CreateObject(Type type, Boolean failIfExists)
   at Microsoft.ServiceModel.DomainServices.Tools.CreateRiaClientFilesTask.CreateSharedTypeService(ClientBuildManager clientBuildManager, IEnumerable`1 serverAssemblies, ILogger logger)
   at Microsoft.ServiceModel.DomainServices.Tools.CreateRiaClientFilesTask.GenerateClientProxies()
   at Microsoft.ServiceModel.DomainServices.Tools.CreateRiaClientFilesTask.ExecuteInternal()
   at Microsoft.ServiceModel.DomainServices.Tools.RiaClientFilesTask.Execute()
   at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute()
   at Microsoft.Build.BackEnd.TaskBuilder.ExecuteInstantiatedTask(ITaskExecutionHost taskExecutionHost, TaskLoggingContext taskLoggingContext, TaskHost taskHost, ItemBucket bucket, TaskExecutionMode howToExecuteTask, Boolean& taskResult)

WRN: Assembly binding logging is turned OFF.
To enable assembly bind failure logging, set the registry value [HKLM\Software\Microsoft\Fusion!EnableLog] (DWORD) to 1.
Note: There is some performance penalty associated with assembly bind failure logging.
To turn this feature off, remove the registry value [HKLM\Software\Microsoft\Fusion!EnableLog].
    BusinessApplication2

```