TeleTet : Critical Error

Error creating new session

DEBUG MODE

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

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('5f83137bde943e4ca34e4c7f0cc188a6', -1, 1414052285, 1414052285, '36536711', 1, 0, 0)

Line : 189
File : sessions.php