phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry 'c1f173c0cc1af016ca14cd45539c8918' 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 ('c1f173c0cc1af016ca14cd45539c8918', -1, 1770005426, 1770005426, 'd849d817', -4, 0, 0)

Line : 187
File : sessions.php