With the release of Blackboard SaaS 4000.8 to production last week, Blackboard reported a change that inadvertently may have caused some links to become corrupted.
In a specific scenario where a document included PDF attachments from more than one module, an attachment from a different module may no longer be referenced correctly. In some cases, the document may display an incorrect PDF or an attachment may not open as expected. This may happen with any file types that are cross-referenced (not just PDFs).
For updates, see https://status.blackboard.com/