[Plugin: Auto Post Thumbnail] No thumbnails sitewide

Hi, I need help. This is the first time I install the plugin on my site. All thumbnails are successfully generated, including ‘featured image’ on all post. However, thumbnails are missing all over the site. Is there something I missed? Any other requirement on my host’s end?

Thanks in advance.

http://ww.wp.xz.cn/extend/plugins/auto-post-thumbnail/