Error updating sessions table

DEBUG MODE

SQL Error : 1062 Duplicate entry 'viewforum.php?f=40&sort_order=newest&topicdays=0&_f_=40x' for key 'session_page'

UPDATE phpbb_sessions SET session_time = 1788987806, session_start = 1788987806, session_page = 'viewforum.php?f=40&sort_order=newest&topicdays=0&_f_=40x' WHERE session_id = 'bee14f2ca7d02822b0451f25a936a304'

Line : 556
File : sessions.php