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: Shared Memory Provider, error: 40 - Could not open a connection to SQL Server)
In this post I am going to show you the way to overcome this issue.
Just follow the quick steps:
(i) Open SQL Server Configuration Manager
(ii) Start the selected services as given in image below.
In most cases these steps will fix your issue. Thanks.