The internal link was copied and pasted.
Copying and pasting internal links from within a UC Text or UC Text+Image component will yield broken links. This applies to content that is internally hyperlinked to DAM assets or other CQ pages. It’s important to please check your pages for broken links prior to activation and relink them to the appropriate internal resource. This should be done in Preview Mode.
Note, that moving an entire text or text + image component keeps things in tact.