Symptom

 When running a BTXML script, the Integration errors out with a message about the copies being sourced by a data source or that they must be a constant value.

Environment

BarTender Integration builder

Fix/Answer

When you open up the label, you'll likely find that the copies (or serial numbers if there's a serialization) has a database field in it:

Remove the database field and return it to a constant value

Once you do this, the error message goes away.