This could quite possible be an issue with thumbnails itself on your site. Could you try using this plugin below to see if the thumbnails start generating ?
Sorry no luck, I've installed an ran the plugin and no dice, what I did is that I created an image field on the custom fields named "Gallery" allowing it to have mutliple instances or the field, on a Custom Post Type Named Inventory I can add several different photos. on a single template I am running a
[wpv-for-each field="wpcf-gallery"]
to create a gallery but when I use this short code
it renders the full size image URL not the thumbnail URL as I was expecting, I also tried with medium and large sizes but it always displays the full size image url.
Also notice that I don't think that is a thumbnails problem because when I add to a test page different sizes of the same images they display correctly.
It seems that something might be causing this because thumbnails do work.
The featured image thumbnail works so what I would do in a case like this is to temporarily disable the non-toolset plugins and try again with the thumbnails for the custom fields to see what happens.
Thanks Shane - not sure what you mean by "the featured image thumbnail works"...
In any case, the problem seems to stem specifically from using the [types field] shortcode inside of the [wpv-for-each] and <wpv-loop>.
If we use the short code (below) in the body of a post where we have uploaded images, it responds as it should, showing the correct URL of the alternate size image:
[types field='gallery' size='thumb' separator=', ' url='true'][/types]
Otherwise, when placed into a loop it only shows the original image URL.
But to be extra vigilant, we did disable all the plugins (except for toolset plugins) and we still ran into the same issue.
It was NOT a toolset bug or problem, it was a conflict with a third party plugin that impeded Toolset from recording the image sizes when they were uploaded - the plugin was an image watermark plugin. We couldn't isolate the problem because it only occurred when the images were uploaded, so even deactivating the plugin wouldn't retroactively fix the problem.