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 ('02df2c1cfd3cf07fdb004fdf5d2d3fde', -1, 1752904700, 1752904700, 'd849d88f', 2, 0, 0)

Line : 189
File : sessions.php