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 ('d1436f6b936d85c32e490af1b2070fe7', -1, 1711646571, 1711646571, '035407ff', -7, 0, 0)

Line : 187
File : sessions.php