Reply to: DTD not found error!June 10, 2014 at 8:38 pm
This shouldn't be an issue. If you can provide the file that the user was working with to XMetaL Support they would be happy to test it to see if they can reproduce the issue.
It isn't clear from your message whether this is an ongoing issue for this person. Perhaps it was some kind of temporary glitch.
If the issue persists and you cannot reproduce it I would suggest reinstalling. It could be that the catalog files used for DITA or some other files that make up that part of the DITA authoring experience have been modified, corrupted or removed.