As far as we know, Atlassian© never released validation tool for Confluence©. It might be not accidental. Confluence© internally relies on an object storage, which is very difficult to validate and repair. If something went wrong, there is often no way to trace for the reasons. There remains just an abstract object ID. You cannot even guess, if it were a document or a page and what was the name. As a result, Confluence© servers accumulate errors for years, while clients sometimes do not even suspect it.
On another hand, Enterprise Bridge must validate Confluence© space before migration because it must further reconstruct all content inside SharePoint©. We often discover various errors on Confluence© servers of our clients during migration. Corrupted documents, missing pages, broken links are just a few common types of such errors. Enterprise Bridge scrupulously reports all such errors. Are these errors of Enterprise Bridge? Probably not. Can you recover missing content from these errors? Probably not either. It is just a reality of migration from Confluence, which Enterprise Bridge reveals for you.
