Error: 500 Internal Server Error

Sorry, the requested URL 'http://localhost/reader?url=https://www.rockymounttelegram.com/news/world/a-retiring-castro-to-bring-younger-face-to-cubas-communists/article_9995163d-b82c-5563-a19c-50a964a52a2d.html' caused an error:

Unhandled exception