My default thumbnail size is 150×150. Therefore, if I use a custom thumbnail size, such as 75×75 it should use the thumbnail of 150×150 and shrink to fit to my size:
get_the_post_thumbnail( $item->ID, array(75,75))
However, it is basing the image off of a thumbnail size of 149×100. The 150×150 image exists, but it refuses to use it.
I figured heck with that, I’ll just create a custom 75×75 thumbnail and that will solve the problem:
functions.php
add_image_size( 'listp-thumb', 75, 75, true ); // thumbnails located in list posts
Now to call the new thumbnail:
get_the_post_thumbnail( $item->ID, 'listp-thumb')
The same thing happens. 🙁 Do I need to clear a custom query that may be interfering with this?
Try installing Ajax Rebuild Thumbnails
This will create the new image size.