The specified named connection is either not found in the co

Question

I've uploaded my entity framework project on my hosting. the web.config file contain the following connection string

<add name="CoreEntities" connectionString="metadata=res://*/App_Code.Model.csdl|res://*/App_Code.Model.ssdl|res://*/App_Code.Model.msl;provider=System.Data.SqlClient;provider connection string="data source=adress of my datatbase ;initial catalog=Core; User ID=xxx; Password=yyy;multipleactiveresultsets=True;App=EntityFramework""
      providerName="System.Data.EntityClient" />

but when i open my web page i get the following error:

The specified named connection is either not found in the configuration, not intended to be used with the EntityClient provider, or not valid

 
kindly tell me what wrong that this error is occurred.
thanks in advance