phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '6720052bddd400e0c64381e6e1cc17b7' 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 ('6720052bddd400e0c64381e6e1cc17b7', -1, 1788580192, 1788580192, 'c0a81013', -501, 0, 0)

Line : 187
File : sessions.php