phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry 'cc94b0ffb0ffed950ba20e7de2cb38b5' 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 ('cc94b0ffb0ffed950ba20e7de2cb38b5', -1, 1418944248, 1418944248, '3691bf0e', -1, 0, 0)

Line : 187
File : sessions.php