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 ('12702ee9308be65603c15c1bd18cc7cd', -1, 1730415841, 1730415841, '12776ab0', 18, 0, 0)

Line : 195
File : sessions.php