phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry 'b3864aefaf3fc2ff8ab0e824c077b6c8' for key 1

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('b3864aefaf3fc2ff8ab0e824c077b6c8', -1, 1419080764, 1419080764, '3657b4b5', -1, 0, 0)

Line : 187
File : sessions.php