phpBB : Critical Error

Error creating new session

DEBUG MODE

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

INSERT INTO elranchito_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('51eb75e3782c4a277e6a7e988bcabefb', -1, 1469419978, 1469419978, '36508e9b', 3, 0, 0)

Line : 172
File : sessions.php