Before going any further, validate the output. Currently, Bruno only validates input, not output.
If your ambition is to have audio in this DTB, you can now open the DTB in your production tool and start recording. Start the production tool, select "open", and browse to the folder that you selected as output path in step 3 above.
modify fileset option in the file set tab of the lpStudio/Pro main screen for example). The MDF included by Bruno is a dummy and does not represent the true markup definition.