Embed CxF data (import)
In order to import CxF information CxF XML files need to be present in a folder and their name has to be the spot color name that it represents.
Open a PDF/X file
The PDF needs to be a PDF/X file or has to have at least an PDF/X Output Intent entry, since the CxF information is being embedded into the Output Intent entry. If there is no Output Intent entry present the "Execute" button in pdfToolbox cannot be hit.