phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '709e7b456a0d0b0a444af8c22692026c' for key 1

INSERT INTO phpbb2_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('709e7b456a0d0b0a444af8c22692026c', -1, 1493409452, 1493409452, '3651e620', 17, 0, 0)

Line : 187
File : sessions.php