The underlying provider failed to open Entity Exception

[garry79]

I've installed VS 2012 Pro followed by SQL Server 2012 Express. I then joined one solution to another so they share the same APP_DATA folder. Both projects have SQL server mdf databases in the APP_DATA folder (created before I installed SQL Server 2012 instance).

In a class library project for one of these websites, I added an Entity Manager Model and data access file. For some reason the data access file couldn't locate the connection string, so I added the the connection string from the app.config in the class library to the web.config file for that website. Unfortunately, now I get the following error:
The underlying provider failed to open Entity Exception.

Here is the connection string from the web.config :

<connectionStrings>
<add name="OrchidFamilyDBEntities" connectionString="metadata=res://*/OrchidFamilyModel.csdl|res://*/OrchidFamilyModel.ssdl|res://*/OrchidFamilyModel.msl;provider=System.Data.SqlClient;provider connection string=&quot;data source=(LocalDB)\v11.0;attachdbfilename=|DataDirectory|\OrchidFamilyDB.mdf;integrated security=True;multipleactiveresultsets=True;application name=EntityFramework&quot;" providerName="System.Data.EntityClient" />
</connectionStrings>

Why am I not able to connect to the database?

Thanks in advance!