WP在线商城 网页打不开了 Not Found

后台和商城主页都能打开，但具体到某个产品就打不开了，Not Found， 有遇到相同问题的朋友能帮忙说下问题所在吗？谢谢。 
Not Found

The requested URL /product-category/cutting-plotter/ was not found on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.