phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '40886b400d4b459019d11b38f62a3f8f' for key 'PRIMARY'

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('40886b400d4b459019d11b38f62a3f8f', -1, 1406776891, 1406776891, '3651b18c', -4, 0, 0)

Line : 245
File : sessions.php