I’m comparing the changes between the revisions of a document, viewing them in Rendered mode, and the following message appears at the top of the rendered
Warning: For security reasons, at least one of the compared documents is displayed in restricted mode as it is not the current version. There may be differences and errors due to this.
For what I can see, the document has just textual edits, I see no code or the like; the edited text contains links to outside URLs, but nothing else.