phpBB : Erro Crítico

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '-1' for key 2

INSERT INTO f_activesessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('856546d5487961bbe17943f05da342a6', -1, 1766611972, 1766611972, 'd849d817', 7, 0, 0)

Line : 187
File : sessions.php