phpBB : Fatale Fout

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 ('36231c11c9168e74c78e32f6267fa3bb', -1, 1414792781, 1414792781, '36a1936a', 3, 0, 0)

Line : 186
File : sessions.php