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 ('509947b87c531f32ad8c55d33f7df557', -1, 1561449527, 1561449527, '36a3d595', -9, 0, 0)

Line : 187
File : sessions.php