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 ('c3c8ff7b3d58b8e18a6db487bca0f9ec', -1, 1711672875, 1711672875, '2cc8b38a', -7, 0, 0)

Line : 187
File : sessions.php