As of the moment, Tribulant (https://wordpress.org/plugins/slideshow-gallery/) is my favorite WordPress image gallery plugin for the following reasons:
- It’s free
- It’s responsive
- It has a thumbnail feature
- It has a lightbox feature
- It’s relatively easy to use
But is is not without flaws. I noticed that some of the thumbnails were not displaying like so:
And it’s happening across all my browsers and devices. I deducted from testing that it’s a plugin issue. And by finding the common denominator in all the images having issues, I found out what the problem is.
It’s an issue on how the plugin creates or names thumbnail files. I found out that if an image’s original file name has periods or dots, it screws up the thumbnail.
1) Rename your file so that it does not have periods or dots in the file name. Do this to the original file you have on your computer, not to the one already on WordPress.
2) Re-upload it on WordPress.
3) Use the new file you uploaded.
*you may delete the old image if you’re not using it elsewhere.
Good luck. 🙂