The solution I proposed above as jlennane worked for me. You can find the wp-config-sample.php in the WR root.
Then modify the following parameters to match the schema you created in your MySql data base.
Finally, save it into the WP root as wp-sample.php
/** The name of the database for WordPress */
define(‘DB_NAME’, ‘your schema name on MySql’);
/** MySQL database username */
define(‘DB_USER’, ‘root or your user name’);
/** MySQL database password */
define(‘DB_PASSWORD’, ‘password from your Mysql Db schema’);
So simple but took a while to find.
WP must have a valid wp-config.php file to run.
The problem is that this file doesn’t exist on a new install. At least in 4.6 it doesn’t.
Therefore, WP cannot make the initial connection to the Db. The parameters to connect to the Db are listed in the wp-config-sample, but must be edited, so it’s a chicken and egg problem.
The fix is to edit the wp-config-sample.php file by filling in a few Db data connection items, then just storing the edited file as wp-config.php
Away you will go!
A nice fix by Wp would be to have the Db Dialog screen create a corrected wp-config.php file.