phpBB : 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 ('ee228e3d28d5a3baa49afe32c5e18c3a', -1, 1406092684, 1406092684, '36e0b362', 50, 0, 0)

Line : 180
File : sessions.php