Seems that the icon is missing from imagur
Missing image
Plugin has been updated with a new image URL: https://i.postimg.cc/JzWfmntW/v5sdNHg.png
oLRed69
Mine did the same thing with the update. You have to either go inside the .cs file and grab the new URL to the image and paste that into the config file, or go to each page where the author updated the config file on the page, I can't remember which but one of them still has the imgur url, so that one you'll have to go in to the .cs file.
Don't forget to reload each one on the server after you save the changed config file.