phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '-1' for key 'session_user_id'

INSERT INTO sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('9042da9a3341c570fc63a5fbb1e72e11', -1, 1748800719, 1748800719, 'd849d8de', 2, 0, 0)

Line : 187
File : sessions.php