EntityFramework connect to Visual Studio SQL Server (localdb) - entity-framework

Question

I am running a local instance of Sql Server through Visual Studio:
It is online and I am able to view the data in the database through the UI.
My App.config file looks like the following:
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
<section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false"/>
</configSections>
<connectionStrings>
<add name="EntitiesContext" connectionString="Data Source=(localdb)\MSSQLLocalDB;Initial Catalog=master;Integrated Security=True;Connect Timeout=30;Encrypt=False;TrustServerCertificate=False;ApplicationIntent=ReadWrite;MultiSubnetFailover=False" providerName="System.Data.SqlClient"/>
<add name="DefaultConnection" connectionString="Data Source=(localdb)\MSSQLLocalDB;Initial Catalog=master;Integrated Security=True;Connect Timeout=30;Encrypt=False;TrustServerCertificate=False;ApplicationIntent=ReadWrite;MultiSubnetFailover=False" providerName="System.Data.SqlClient" />
</connectionStrings>
<entityFramework>
<defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework">
<parameters>
<parameter value="mssqllocaldb" />
</parameters>
</defaultConnectionFactory>
<providers>
<provider invariantName="System.Data.SqlClient"
type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
</providers>
</entityFramework>
<startup><supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1"/></startup>
</configuration>
And my EntitiesContext looks like the following:
Could someone please help with what I am missing as this keeps failing connection with the following:
System.Data.SqlClient.SqlException: 'A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)'
Inner Exception
Win32Exception: The system cannot find the file specified

Answer 1

The issue is that the connection string you are using is reverting to a named pipe connection, and it's telling you that nothing is listening on that Pipe.
Changing it to "localhost\MSSQLLocalDB;...." should work if your local database is set up for Shared Memory connections.
To check what protocols are enabled on your server you can run MMC.exe then add the plugin for SQL Server Configuration Manager. Under SQL Server Network Configuration it will show whether your SQL Server instance is allowing Named Pipes or TCP/IP. I believe by default SQL Express only enables Shared Memory which is fine for local testing purposes.