At a certain client, some sort of firewall/ protection mechanism disables the run of Windows's cmd.exe. This is the result when trying to use xlwings:

One workaround would be to write a patch that executes a cmd workaround. We have done this successfully in the past when using xlwings.bas. The problem here is that we are using the add-in version of xlwings xlwings.xlam which is more difficult to patch, since it contains compressed text and not raw text.
As soon as we really need this we can put in the effort and implement such a patch.