Deleted Map file to Update, now thumbnails are broken and didn't update

How do I update thumbnails? I delete the map images from my library to upload a new version and now the thumbnails didn't update to the newer version. I feel like this is a mistake on my part but there wasn't a better forum for this. I tried to clear my cache it didn't help. Google Chrome on Windows 8.1 Extensions:  adblock plus - turned off on roll20 adobe acrobat application launcher for Drive (by google) backstop  google docs offline google mail checker google translate honey malwarebytes browser guard privacy pass session buddy

The thumbnail shows the first largest image on the page. You need to somehow find the deleted, now broken image on the page and also delete it there.

Thank you for your reply. I ended up having to delete the pages. I wish there was a better way but oh well