check if the connection might be blocked by firewall or you need to specify the protocol in your connection string. Read this article it might be helpful for you. http://www.sqlserverlogexplorer.com/database-does-not-exist-access-denied/
check if the connection might be blocked by firewall or you need to specify the protocol in your connection string. Read this article it might be helpful for you. http://www.sqlserverlogexplorer.com/database-does-not-exist-access-denied/