umebius様

コメントありがとうございます。
前後のログを含め以下に記載致します。

--------------------------------------------------
[2017-12-22 01:26:45,710043] eccube.INFO [3a648bfb] [a36590d1] [NULL] [LogListener:logResponse:96] - < 404 [POST, /epsilon_pay_complete.php, 210.254.37.214, NULL, libwww-perl/6.04]

[2017-12-22 01:26:45,703609] eccube.ERROR [NULL] [a36590d1] [NULL] [LogListener:logException:110] - Symfony\Component\HttpKernel\Exception\NotFoundHttpException: No route found for "POST /epsilon_pay_complete.php" (uncaught exception) at /home/********/********.com/public_html/shop/vendor/symfony/http-kernel/EventListener/RouterListener.php line 159 {"exception":"[object] (Symfony\\Component\\HttpKernel\\Exception\\NotFoundHttpException(code: 0): No route found for \"POST /epsilon_pay_complete.php\" at /home/********/********.com/public_html/shop/vendor/symfony/http-kernel/EventListener/RouterListener.php:159, Symfony\\Component\\Routing\\Exception\\ResourceNotFoundException(code: 0): No routes found for \"/epsilon_pay_complete.php\". at /home/********/********.com/public_html/shop/vendor/symfony/routing/Matcher/UrlMatcher.php:98)"} [POST, /epsilon_pay_complete.php, 210.254.37.214, NULL, libwww-perl/6.04]

[2017-12-22 01:26:44,935059] eccube.INFO [NULL] [a3e7a5e1] [NULL] [RouterListener:onKernelRequest:145] - Matched route "shopping_complete". {"route_parameters":{"_controller":"\\Eccube\\Controller\\ShoppingController::complete","_route":"shopping_complete"},"request_uri":"https://shop.********.com/shopping/complete"} [GET, /shopping/complete, ***.***.***.**, https://beta.epsilon.jp/cgi-bin/order/card3.cgi?trans_code=******, Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.84 Safari/537.36]
--------------------------------------------------

epsilon_pay_complete.phpが見つからないとのことですが、対応策がわからず難航しておりました。
ちなみにイプシロン管理画面の決済完了通知先には、仕様書通り｢https://サイトURL/epsilon_pay_complete.php｣と指定しています。
ご教示頂けますと幸いです。