Maria DB which BioStar 2 installs doesn't allow remote access by default. If you have installed the BioStar 2 & database in the server, and need to access the DB from remote place, you need to open this grant by running query below.
GRANT ALL ON *.* TO 'root'@'%' WITH GRANT OPTION;
Above query opens your DB to everyone who access with root account. If you worried about security problems by doing this, you can define client information to restrict the connection.
For an example, if your both server/client system is under the same subnet 192.168.x.x, you can run query like below.
GRANT ALL PRIVILEGES ON *.* TO 'root'@'192.168.%' IDENTIFIED BY '' WITH GRANT OPTION;