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 ('9b5035df80e1bc57473f6ceef72501f1', -1, 1566082698, 1566082698, '03511c5e', 8, 0, 0)

Line : 172
File : /home/rebkell/public_html/boards/includes/sessions.php