Cause

A DT ID which has already been assigned was determined at a function which is a component of a macro for a module.

Solution

1. Locate the function in the schematic using the Go to (graphic) functionality from the popup menu in the Message management dialog.
2. Launch the property dialog of the function.
3. In the properties list, change the value of the DT ID property. Enter a value which has not been assigned yet.
4. Then start a new check run.