Hi marcotungerichunddu,
The reason you are seeing words in English is because the translation is a little outdated. All of our plugins are translated by volunteers, and no one has updated the German one since those strings were changed. Would you be interested in updating the translation? That would fix your site and we’d give you a free license in exchange.
If you are interested, check out the Getting Started post where you’ll find the instructions and files you need. If you are not able to translate it, you’ll unfortunately need to wait for someone else to update the files.
Best,
Leah