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 ('8a4a3ee0854e8e1fdd19e9794e7861b7', -1, 1711691696, 1711691696, '23af717d', -7, 0, 0)

Line : 187
File : sessions.php