phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '-1' for key 2

INSERT INTO didacticaacarigua_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('c7aeba1f0c896f7e79f00c3bbce3194d', -1, 1425076720, 1425076720, '36c55e1e', 1, 0, 0)

Line : 172
File : sessions.php