phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '49aecb397964c3c09a8a5564a3d91bfe' 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 ('49aecb397964c3c09a8a5564a3d91bfe', -1, 1495618881, 1495618881, '36c67666', 6, 0, 0)

Line : 187
File : sessions.php