phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '-1' for key 'session_user_id'

INSERT INTO satshop_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('1c8493f5c3a844354c7dccad9b15a1a2', -1, 1728606871, 1728606871, '2cc05fa1', 13, 0, 0)

Line : 189
File : sessions.php