Including the Word Class when builing an application did not work for me. I still got error 7. To solve this issue I copied manually the class to target computer: "C:\Program Files (x86)\National Instruments\LabVIEW 2018\vi.lib\Utility\NIReport.llb\Word\NI_Word.lvclass". Afterwards the error 7 disappeared and a report was printed. Still I also included the class when building the file.