Unfortunately in my case there was some issue with connecting to PostgreSQL database. I had message something like "Login disallowed". I spent a lot of time to figure out the right solution, which I am going to share with you.
Just go to file on this path - phpPgAdmin/conf/config.inc.php and just change
$conf['extra_login_security'] = true
on
$conf['extra_login_security'] = false
Reference : [1] PhpPgAdmin Home Page [2] XAMPP Home Page