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 ('9df9ed62b759a017a26683a7a81b6c7c', -1, 1711706466, 1711706466, '3417c991', 2, 0, 0)

Line : 187
File : sessions.php