phpBB : Critical Error

Error creating new session

DEBUG MODE

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

INSERT INTO mex2mex_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in) VALUES ('eb7847a372b1d4e5774c174531e05592', -1, 1406320413, 1406320413, '36598aee', 7, 0)

Line : 170
File : sessions.php