If you view the HTML page source, the output for the controlNav thumbnails is:
<ol class="flex-control-nav flex-control-thumbs> <li><img src="undefined" class></li> <li><img src="undefined" class></li> </ol>
Overview of Application:
A view of a content type (Product) contains a view Relationship of type "Entity Reference" to display related imagery (Product Colors) in a FlexSlider of type "Slider with controlNav pattern" like http://flexslider.woothemes.com/thumbnail-controlnav.html. The FlexSlider settings are correct and working as expected, just no thumbnail images.
Parts of the FlexSlider are working:
The view field for Product Color Image when used as the main slide image is successfully getting the proper data from the view Relationship and the image source for the "main" slide images work. They also work when just displaying a single slider of images, or when used creating a combination 2 FlexSliders for a main slide slider and carousel navigation combo.
Alternate configurations of image styles were tested and had the same missing image source:
- Using an image style
- Using a Picture module breakpoint + image style definition
Modules enabled for some background, but this has been isolated as a FlexSlider issue:
- FlexSlider (7.x-2.x-dev) this bug also happened on 7.x-2.x-alpha1
- FlexSlider Views Slideshow (7.x-2.x-dev)
- FlexSlider Views Style
- Picture - FlexSlider Picture (7.x-1.1+46-dev)
- Picture - (7.x-1.1+46-dev)
- Views - 7.x-3.7
- Views Slideshow - 7.x-3.0
Patch: a developer on our team has created a patch and will post soon with a more technical explanation about the root cause and the fix.
Issue queue: I'm not sure if this should be in Flexslider Views Slideshow or for the FlexSlider views style plugin. Maintainers - please reclassify if needed.