So, if you found this blog post, I assume you’ve run into this particular problem in your installation of Confluence. And you’ve probably also found the Atlassian KB article, RuntimeException Multiple AttachmentData objects were returned when only one was expected, which is only marginally helpful at best. The “resolution” suggested by Atlassian — “Rename the attachment and upload again” — is not a resolution at all. It’s a workaround. It doesn’t even acknowledge the root cause of the problem: that Confluence and its underlying database disagree on the definition of integral attachment data, and the database somehow ends up storing data that Confluence doesn’t like. Of course, when a problem is worked around rather than resolved, it’s bound to come up again. In this particular case, as long [...]