I'm getting an unexplained error when running the application today. Everything was running fine last week. When I run application today I get the following error:
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: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)
I haven't changed the web.config file or SQL. Any ideas as to why this is happening?