If you are seeing an error box where your file's thumbnail image should be within your Library, Album view, Tag view or even in the editing tool, the culprit may be your internet browser's ad blocker.
It's best to first check your browser's ad blocker to make sure it isn't blocking anything on Forever.com. Since we do not have any ads of any sort it should not be but ad blockers can sometimes pick up things that are not actually ads.
To make sure your ad blocker does not stop Forever.com from loading all of your file's thumbnail images you can white-list Forever.com within your ad blocker.
If you have any further questions please reach out to firstname.lastname@example.org.