Conoha VPS Kusanagi で HTTP ERROR 500

深夜0時あたりを境に突然サイトがHTTP ERROR 500になりました。

エラーが発生した前後で特にサーバーの設定やPHP関連は触っておらず
エラーログを確認すると下記のエラーが継続して発生しています。

エラーログ

html
12020/06/06 02:43:55 [info] 9558#0: [ngx_pagespeed 1.13.35.2-0] No threading detected. Own threads: 1 Rewrite, 1 Expensive Rewrite.
22020/06/06 02:43:55 [info] 9558#0: pagespeed: rollback gzip, explicit configuration in /etc/nginx/nginx.conf:39
32020/06/06 02:43:55 [alert] 9563#0: detected a LuaJIT version which is not OpenResty's; many optimizations will be disabled and performance will be compromised (see https://github.com/openresty/luajit2 for OpenResty's LuaJIT or, even better, consider using the OpenResty releases from https://openresty.org/en/download.html)
42020/06/06 02:43:55 [error] 9563#0: lua_load_resty_core failed to load the resty.core module from https://github.com/openresty/lua-resty-core; ensure you are using an OpenResty release from https://openresty.org/en/download.html (rc: 2, reason: module 'resty.core' not found:
5        no field package.preload['resty.core']
6        no file './resty/core.lua'
7        no file '/usr/share/luajit-2.0.4/resty/core.lua'
8        no file '/usr/local/share/lua/5.1/resty/core.lua'
9        no file '/usr/local/share/lua/5.1/resty/core/init.lua'
10        no file '/usr/share/lua/5.1/resty/core.lua'
11        no file '/usr/share/lua/5.1/resty/core/init.lua'
12        no file './resty/core.so'
13        no file '/usr/local/lib/lua/5.1/resty/core.so'
14        no file '/usr/lib64/lua/5.1/resty/core.so'
15        no file '/usr/local/lib/lua/5.1/loadall.so'
16        no file './resty.so'
17        no file '/usr/local/lib/lua/5.1/resty.so'
18        no file '/usr/lib64/lua/5.1/resty.so'
19        no file '/usr/local/lib/lua/5.1/loadall.so')