no related posts breaks website

hello and first, thank you for this plugin.
second, thank you for adding a debug mode. It helped!

So, I experienced a bug for which I spend 2 hours and I found out it’s because of your plugin. How? I just created a new post and the output was broken when I previewed or published it. It happened for every new empty post I created, and I was totally confused and scared my WP database was broken.

By carefully analyzing the HTML generated, I found out that’s because the DIV that closes relpost-thumb-wrapper is missing. This is because my new posts didn’t have any related taxonomy/tag with other posts (new category I created).

Reason why it breaks pages: When your plugin doesn’t find related terms, it calls the return $this->finish_process in the file related-posts-thumbnails.php.

The problem is that your finish_process function outputs what’s in $output string and this contains an opening DIV at line 341. Since no /DIV is appended to this string when you return with the finish_process, it breaks everything in the page after your filter is applied!
You have this problem at 5 different places:

345: Posts number is 0
377: No taxonomy terms to get posts
395: No categories were selected
443: No posts matching relationships criteria
454: No posts found

every time you return exit function with no related posts generated, it breaks the page.

I suggest that you just reset $output before calling it when you have to call the function at the lines mentioned above. that’s what I did and it solved the problem.
It makes sense that you should not output anything at all whenever your plugin can’t find related posts.

also, I am very surprised to be the first to stumble upon this BLATANT bug.
no harm done, just update your plugin and I’ll give you 5 stars 🙂

The page I need help with: [log in to see the link]