Database connection error

Hi I’m trying to install Invoice Plane on my php hosting .Everything is smooth , regarding access rights and database details.The system responds with a green button “The database is successfully configured.” But when I press next a message appears saying “Unable to connect to your database server using the provided settings. Filename: /var/www/vhosts/ Line Number: 99”

I’ve ckecked no tables in the database , no development folder created , database.php has the right info, any ideas why this happens?

Thanks in advance