Dumping the plugin data shows thumbnail_url = null, and all the thumbnails cached in the uploads folder shows "Image not found". Have a look at https://nybokjokken.no/ at the bottom of the front page to see what the error looks like.
I've tried updating to October CMS 2.0, but nothing changes. The site is currently running the latest version before the 2.0 update.
I went over the code to see if there were any changes in partials. Did the latest update change anything when it comes to thumbnail generation?
i tested and found the problem, issued an update. Install it, after installation, clear the cache of the site and refresh the page, images should appear!