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 ('79c25cff0765c9583592fb0a2e705eb4', -1, 1711647061, 1711647061, '36d3cb2d', -7, 0, 0)

Line : 187
File : sessions.php