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 ('c9ae3ff6d9ef3ef2084bbd67399688ba', -1, 1422609686, 1422609686, '36e30962', 1, 0, 0)

Line : 172
File : sessions.php