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 ('88d2139b9a0047efda07d3b0886466ce', -1, 1711648446, 1711648446, '03ec13fb', -4, 0, 0)

Line : 187
File : sessions.php