phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '8c720e2713fb0cc5da5da202b4b4ee21' for key 'phpbb_sessions.PRIMARY'

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('8c720e2713fb0cc5da5da202b4b4ee21', -1, 1768923064, 1768923064, '126109af', -4, 0, 0)

Line : 187
File : sessions.php