Plastic framework catch error:

type:User Error
message:Plastic workshop: Database connection failed
file:/home/kotelbizon/domains/kotelbizon.com.ua/public_html/workshop/db.php
line:45
code:256


Backtrace:
/home/kotelbizon/domains/kotelbizon.com.ua/public_html/workshop/db.php line: 45
/home/kotelbizon/domains/kotelbizon.com.ua/public_html/workshop/db.php line: 29
/home/kotelbizon/domains/kotelbizon.com.ua/public_html/workshop/application.php line: 37
/home/kotelbizon/domains/kotelbizon.com.ua/public_html/index.php line: 13