参考".dll"这是不能添加的

在我的解决方案中的一个项目中，我有以下代码来生成.dll程序集。主要是通过msdn文档和stackoverflow上的另一个问题的答案开发的。代码构建和运行良好，"。dll"程序集在项目的bin'debug文件夹中生成。但是，我在解决方案中的其他项目中引用程序集时遇到了问题。我右键单击references-> add reference并选择"。dll"文件。当我单击ok时，我得到这个问题标题中所述的错误消息。谢谢。

        // Retrieve application domain ie environment where applications execute
        // This is done because if an assembly is loaded into the default 
        // application domain it cannot be unloaded from memory while the process
        // is running. However if another application domain is opened to load
        // and execute the assembly, the assembly is unloaded when the application
        // domain is unloaded. 
        AppDomain currentDomain = AppDomain.CurrentDomain;
        // Now create a dynamic assembly in the current application domain
        // and allow it to be executed and saved to disk
        AssemblyName name = new AssemblyName("FieldIdEnum");
        AssemblyBuilder assemblyBuilder = currentDomain.DefineDynamicAssembly(name,
            AssemblyBuilderAccess.RunAndSave);
        // Now we define a dynamic module in the assembly that was just created
        // For this single single module assembly the module has the same name as 
        // the assembly
        ModuleBuilder moduleBuilder = assemblyBuilder.DefineDynamicModule(name.Name,
            name.Name + ".dll");
        // Now we define the public enumeration with the name "DbFieldId" and an
        // underlying type of Integer
        EnumBuilder myEnumBuilder = moduleBuilder.DefineEnum("EnumeratedTypes.DbFieldId",
            TypeAttributes.Public, typeof(int));
        // Now retrieve the FieldId table from the database, bear in mind that the
        // string description will have white spaces, these need to be trimmed 
        // otherwise they are invalid for enum
        // For this to work a reference was added to ConsoleApplication4 and
        // Entity Framework
        using (FieldIdEntities dbEntities = new FieldIdEntities())
        {
            var lines = dbEntities.CSV_FIELD_DETAILS;
            foreach (var field in lines)
            {
                myEnumBuilder.DefineLiteral(field.DESCRIPTION.Replace(" ", String.Empty),               (int)field.FIELD_ID);
            }
        }
        // Now create the enum
        myEnumBuilder.CreateType();
        // If good so far save the assembly:
        assemblyBuilder.Save(name.Name + "dll");