ERROR: PleskFatalException

Hi all.

i have this error.

ERROR: PleskFatalException
Unable to connect to database: mysql_connect() [<a href='function.mysql-connect'>function.mysql-connect</a>]: Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)

0: common_func.php3:146
psaerror(string 'Unable to connect to database: mysql_connect() [<a href='function.mysql-connect'>function.mysql-connect</a>]: Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)')
1:...

ERROR: PleskFatalException