phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '9f77f237dec4e2e631d023a1d9483c8c' 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 ('9f77f237dec4e2e631d023a1d9483c8c', -1, 1771185155, 1771185155, 'd849d8a7', 8, 0, 0)

Line : 187
File : sessions.php