phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '84d8674c1d18ce67d5551a5426602587' 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 ('84d8674c1d18ce67d5551a5426602587', -1, 1770006563, 1770006563, 'd849d817', -4, 0, 0)

Line : 187
File : sessions.php