I have given up installing Office 2019. C2R v6.4.5 , OTool, KMS Tools Portable all do NOT work for me. I have tried several times on different machines. The errors I get have been "There is no license key installed", "There is no script file specified", the Install Office button will do nothing, no matter that Office was both mounted and placed at the same folder as the tool executable. It would say "completed", but Office would still require activation.
Going back to Office 2016 until a more reliable tool exist. This has been a nerve-draining struggle for many hours already and I do not understand how it works for some people, providing I have followed their exact instructions.
Perhaps if someone can create an extensive walkthrough, such as download this, place it there, run this as an administrator, check this, uncheck that, select that from the dropdown menu, enable/disable internet, click this button, do not run, but activate through that tool and that button providing you have entered these parameters, etc....