Problem solved by trashing the preferences. Such a simple fix, I should have tried it earlier.
For the record, it was happening with all of the preset and custom output module settings.
For those in the same boat, to trash the preferences you press Ctrl+Alt+Shift (Windows) or Command+Option+Shift (Mac OS) when you click on the application to launch it. It will then ask you if you want to trash the preferences.
That’s it.
Nathan