We were able to connect to the database server (which means your username and password is okay) but not able to select the lacostac_mi2018
database.
lacostac_mi2018
have permission to use the lacostac_mi2018
database?username_lacostac_mi2018
. Could that be the problem?If you don’t know how to set up a database you should contact your host. If all else fails you may find help at the WordPress Support Forums.