There are also variants that don't have the "Using navigation title as fallback." sentence.Unable to retrieve linktext from target: '<file_name>.dita'. Using navigation title as fallback.
I also get errors like this:
However when I open the identified topic and click the link, the <another_file_name>.dita appears normally (in both the source authoring space and in WebHelp).The file ../subdirectory/<another_file_name>.dita is not available to resolve link information.
What do these errors mean and how do I resolve them?