We are terribly sorry for the inconvenience, current version can correctly work with non-English versions of Hyper-V only when English locale is selected (date,time, numbers format). You can customize the locale to be fully identical to your German locale (i.e. comma as a decimal separator), but the name of the locale should be English. We are currently working to fix the issue.
Let us know if you have any issues implementing a workaround. Again, please accept our apologies for the inconvenience, we hope a fixed version is going to be available soon.