Thumbnails are Black

Looks like the thumbnails are defaulting to a blank image.

https://englebright.biz/wp-content/themes/widescreen/images/thumb-bg.jpg

How are you generating that thumbnail? If it’s via the theme then you need to seek support at the theme provider’s web site.

https://graphpaperpress.com/support/

I am generating the thumbnails via WordPress. This is the procedure I follow:
– In my WordPress dashboard I click on “New Post”
– I write my post.
– Using the PhotoShelter plugin I upload an image from my PhotoShelter site.
– I then publish the post.

Thanks