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 ('896238d1f7d1a50896fde2b3d741ba74', -1, 1711622696, 1711622696, '6418148d', -4, 0, 0)

Line : 187
File : sessions.php