Cannot Delete Preview Image

By dzerbs 

I uploaded a blend a while ago, a little before V5. Because of the new layout and the squared images, some of the preview image was cropped off. It wasn't that big of a deal to just just crop it myself so it shows my model. But the problem is that I can't delete the old one. So now I have two  preview images, the off center one and the centered one. I would like to just have the centered one. The little trash icon isn't working when editing the blend, in the manage files part. The blend I'm having this problem with is my Toy Train one, Thanks for any help, really liking the new site even though theres a few stuff here and there that doesn't work sometimes, but I'm sure it will be fixed soon, you guys are great!