ASP + EF loading assembly problem

I have a big problem. When I'm running asp SOMETIMES the application is craching with the following error message:

Schema specified is not valid. Errors: The types in the assembly 'Data.EF, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' cannot be loaded because the assembly contains the EdmSchemaAttribute, and the closure of types is being loaded by name. Loading by both name and attribute is not allowed.

Stack Trace:

[MetadataException: Schema specified is not valid. Errors: The types in the assembly 'Data.EF, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' cannot be loaded because the assembly contains the EdmSchemaAttribute, and the closure of types is being loaded by name. Loading by both name and attribute is not allowed.]

System.Data.Metadata.Edm.ObjectItemCollection.LoadAssemblyFromCache(ObjectItemCollection objectItemCollection, Assembly assembly, Boolean loadReferencedAssemblies, EdmItemCollection edmItemCollection, Action1 logLoadMessage) +480

System.Data.Metadata.Edm.ObjectItemCollection.ExplicitLoadFromAssembly(Assembly assembly, EdmItemCollection edmItemCollection, Action1 logLoadMessage) +53

System.Data.Metadata.Edm.MetadataWorkspace.ExplicitLoadFromAssembly(Assembly assembly, ObjectItemCollection collection, Action1 logLoadMessage) +93 System.Data.Metadata.Edm.MetadataWorkspace.LoadFromAssembly(Assembly assembly, Action1 logLoadMessage) +130 System.Web.UI.WebControls.EntityDataSourceView.ConstructContext() +585 System.Web.UI.WebControls.EntityDataSourceView.ExecuteSelect(DataSourceSelectArguments arguments) +76

System.Web.UI.DataSourceView.Select(DataSourceSelectArguments arguments, DataSourceViewSelectCallback callback) +21 System.Web.UI.WebControls.DataBoundControl.PerformSelect() +143 Telerik.Web.UI.GridTableView.PerformSelect() +38 System.Web.UI.WebControls.BaseDataBoundControl.DataBind() +74 Telerik.Web.UI.GridTableView.DataBind() +363 Telerik.Web.UI.RadGrid.DataBind() +173 System.Web.UI.WebControls.BaseDataBoundControl.EnsureDataBound() +66 Sys开发者_如何转开发tem.Web.UI.WebControls.CompositeDataBoundControl.CreateChildControls() +75 System.Web.UI.Control.EnsureChildControls() +102 Telerik.Web.UI.GridBaseDataList.get_Controls() +33 Telerik.Web.UI.RadAjaxControl.PopulatePlainPanels(Control parent, List`1 list, Control root) +119 Telerik.Web.UI.RadAjaxControl.OnPagePreRender(Object sender, EventArgs e) +1802

System.EventHandler.Invoke(Object sender, EventArgs e) +0

System.Web.UI.Control.OnPreRender(EventArgs e) +8864486

System.Web.UI.Control.PreRenderRecursiveInternal() +103 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2496

I also added LoadFromAssembly before every context call and still the same problem.

context.MetadataWorkspace.LoadFromAssembly(context.GetType().Assembly);

Enviroment: VS 2010, .NET 4.0, C#, EF

Could please somebody help me, to fix this issue?

Thanks in advance,

Best regards.

I was receiving the same error on pages where there was a mixture of EntityDataSource objects and other data access such as ObjectDataSource and/or imperative code.

I took the advice of the MSDN article referenced in the other answer to your question. I.e. to use context.MetadataWorkspace.LoadFromAssembly(...). I actually didn't know how to get a reference to the context instance used by EntityDataSource, and I figured I should DRY it up anyway, so I created a partial class eg:

    public partial class YourTypeNameEntities
{
    partial void OnContextCreated()
    {
        this.MetadataWorkspace.LoadFromAssembly(typeof(Full.Namespace.Of.YourTypeNameEntities).Assembly);

    }

It still didn't work, but I noticed fairly quickly that when calling DataBind() on a control bound to an EntityDataSource that my OnContextCreated() implementation was not firing!

That was a different issue to which I found a solution... replace the ConnectionString and DefaultContainerName attributes in the EntityDataSource declaration with ContextTypeName. For example:

    <asp:EntityDataSource ID="CountrySource" runat="server" 
ContextTypeName="Full.Namespace.Of.YourTypeNameEntities" EntitySetName="Country" 
OrderBy="it.Name" Where="it.Active==true">

That made sure my OnContextCreated implementation would fire and POOF, the "Loading by both name and attribute is not allowed" problem went away!

It's an old post but I've ran throught this problem twice this week and it seems to, in my case at least, to be related about the fact that I opened a VPN (for a complete other task with no link to this entity projet) and then, this error happened.

I've tried to close my VPN... then close my projet and re-open, completly close my VS without any success. But, restarting my computer make it works back.

Hope this helps if someone get this in same circonstences.

I was seeing the same error message, using EF 5.0 and WCF Data Services 5.2.0. This was a data service using a DbContext-derived class.

The fix for me was to separate code-first EF code from model-first EF code. By moving the code-first code into a separate assembly, the error message went away and things are working. The only way I was able to figure out to try this, is that the [EdmSchema] attribute exists on the code generated from our EDMX; but it doesn't exist on our model (code-first) code.

Hope that helps someone...

I was getting the same error for days. I using was a mixture of EntityDataSource objects and other data access such as ObjectDataSource in the same page. Replaced the EntityDataSource objects with ObjectDataSource. Problem went away!