phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry 'f29bff2dd75f552fff8e9c2bfd0b01d4' for key 'PRIMARY'

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('f29bff2dd75f552fff8e9c2bfd0b01d4', -1, 1503564315, 1503564315, '3651c0c0', 4, 0, 0)

Line : 187
File : sessions.php