phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry 'caa6fcdb6563177758c089d77af700e0' 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 ('caa6fcdb6563177758c089d77af700e0', -1, 1493387579, 1493387579, '1714e161', 21, 0, 0)

Line : 187
File : sessions.php