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 ('8c9cee3a22a23a79a85be09eac1033ce', -1, 1571113446, 1571113446, '03e3026d', -10, 0, 0)

Line : 191
File : sessions.php