무료도메인에서 작업 후에 아마존 서버로 이전했는데, 메인페이지에 다음과 같은 오류메세지들이 뜹니다.

Warning: session_start(): open(/var/lib/php/7.0/session/sess_h27una7glolthuvqq8lh0ttsf3, O_RDWR) failed: Permission denied (13) in /data/www/von.news/wp-content/plugins/cosmosfarm-members/cosmosfarm-members.php on line 12
Warning: Unknown: open(/var/lib/php/7.0/session/sess_h27una7glolthuvqq8lh0ttsf3, O_RDWR) failed: Permission denied (13) in Unknown on line 0
Warning: Unknown: Failed to write session data (files). Please verify that the current setting of session.save_path is correct (/var/lib/php/7.0/session) in Unknown on line 0

이건 서버 권한설정의 문제일까요? 조언 좀 부탁드립니다.