Server Error in "/" Application - on anonymous links

We have a lot of documents that are hosted and managed on SharePoint, but linked to from public web pages. All of the sudden several people are reporting that they are encountering this error when trying to access them. I haven't been able to find any pattern to it. Some are logged in, others not. Various browsers. We submitted a ticket, but we were told to generate all new links, which isn't super useful in our situation.