Can't really speak on your specific issue, since my Windows runs with English language. However, I wonder as to why you're looking to use this script? If it is to create your own custom nodes, then I would actually suggest using the MagicNodes script (which is still developed, while this one has been stagnate for two years). I don't believe this script any functionality in that department over MagicNodes, and at this point, this script likely underperforms due to it's lack of development.
The only exclusive functionality I believe this script has that no other does, is the ability to hide some of the built in nodes. For instance, I have several of the "Files to Edit" sub-nodes hidden (such as No Album Art due to the Tagging Inconsistencies script offering that and more). If this is what you're looking for, then I hope someone can solve your issue, otherwise I recommend looking into the MagicNodes script.