Thumbnail issue messes up website

I’ve used this plugin for about four years and I love it. However, one issue crops up every so often and doesn’t go away unless I delete all plugin data; sometimes the plugin fails to display a thumbnail for a post and this messes up the page. The whole page is essentially a link to the post without a thumbnail even when a reader is viewing a different post. I’ve failed to make this go away yet we’ve received numerous complaints about this so much that we are now working on a native hits counter to display most visited posts.