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 ('9afdee45594197610b166a2e4c0843d1', -1, 1711712887, 1711712887, '2cc1d069', -4, 0, 0)

Line : 187
File : sessions.php