If you are using the Microsoft Edge browser, you will see a warning message after downloading the .msi file. In order to run the file, you must first trust MarkStein Publisher. This is done as follows:
Klick on [More Actions]…
… and then on [Keep]. After that the following dialog opens:
Klick on [Show more]…
… and afterwards on [Keep anyway].
After that, you can install the file by selecting [Open file]. Then perform the steps described in “How do I install MarkStein Publisher on a Windows computer?”.