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 ('3c0f00ce3e3dabe669cd723ed4d3e7e4', -1, 1757040806, 1757040806, 'd849d80f', -9, 0, 0)

Line : 247
File : sessions.php