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 ('b9619586acaad6e93931b740b2a1959a', -1, 1770046836, 1770046836, 'd849d87f', 6, 0, 0)

Line : 187
File : sessions.php