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 ('3c24d3b1ef81d68a1a68d642ac4ecb3f', -1, 1406276645, 1406276645, '3653f158', 7, 0)

Line : 170
File : sessions.php