The Like Box plugin is deprecated and will stop working on June 23rd 2015

With the release of Graph API v2.3, the Like Box plugin is deprecated and will stop working on June 23rd 2015. Use the new Page Plugin instead. The Page Plugin allows you to embed a simple feed of content from a Page into your websites.

https://developers.facebook.com/docs/plugins/like-box-for-pages

差替えないといけないのかな。