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 ('dfc0d5410e8eeb7ebad2d79e1c65b5f7', -1, 1711691910, 1711691910, '2cdd5772', -4, 0, 0)

Line : 187
File : sessions.php