GenericArguments[0], 'DataLayer.TestContext', on
'System.Data.Entity.IDatabaseInitializer`1[TContext]' violates the 
constraint of type parameter 'TContext'.

<contexts>
    <context type=" DataLayer.TestContext, DataLayer">
      <databaseInitializer type="System.Data.Entity.DropCreateDatabaseAlways`1[
                           [DataLayer.TestContext, DataLayer]], EntityFramework" />
    </context>
  </contexts>

An error occurred during the processing of a configuration file required to service this request.
Please review the specific error details below and modify your configuration file appropriately

Could not install package 'EntityFramework 4.3.1'. You are trying to install this package into a project that targets 'Silverlight,Version=v5.0', but the package does not contain any assembly references that are compatible with that framework. 

Silverlight does not enable you to directly enumerate over a data service query.
This is because enumeration automatically send a synchronous request to the data service.
Because Silverlight only supports  asynchronous operations, you must instead call BeginExecute and EndExecute method to obtain a query result that supports enumeration. 

This topic provides information about the way in which LINQ queries are composed and executed when you are using the WCF Data Services client and limitations of using LINQ to query a data service that implements the Open Data Protocol (OData). For more information about composing and executing queries against an OData-based data service, see Querying the Data Service (WCF Data Services).
Composing LINQ Queries
LINQ enables you to compose queries against a collection of objects that implements IEnumerable. Both the Add Service Reference dialog box in Visual Studio and the DataSvcUtil.exe tool are used to generate a representation of an OData service as an entity container class that inherits from DataServiceContext, as well as objects that represent the entities returned in feeds. These tools also generate properties on the entity container class for the collections that are exposed as feeds by the service. Each of these properties of the class that encapsulates the data service return a DataServiceQuery. Because the DataServiceQuery class implements the IQueryable interface defined by LINQ, the WCF Data Services you can compose a LINQ query against feeds exposed by the data service, which are translated by the client library into a query request URI that is sent to the data service on execution.
 Note:
The set of queries expressible in the LINQ syntax is broader than those enabled in the URI syntax that is used by OData data services. A NotSupportedException is raised when the query cannot be mapped to a URI in the target data service. For more information, see the Unsupported LINQ Methods in this topic.