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 ('9d3f3e5a713f5ed0818e362856a73d59', -1, 1711712917, 1711712917, '2cdcb6c6', -8, 0, 0)

Line : 187
File : sessions.php