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 ('9ab09b423d5e68dae567e3e4fc207334', -1, 1728965038, 1728965038, '23ad3012', -7, 0, 0)

Line : 172
File : sessions.php