Please try the following after starting the hörbert software and inserting the SD card. In the software menu at the top, go to Extras -> Select destination manually. The card should then be selectable there.
If this is not possible, our development department has taken precautions:
You can simply select a file folder on your hard drive - and not your memory card. After that, the hörbert software works on the file folder as if it *were* a memory card. And if your memory card is usable with the card reader under your operating system and mounted correctly, you can simply copy the contents of this folder to the memory card afterwards. This feature is intended for when the memory card's mount directory still doesn't work for some reason, and when alternatives like "Sox" also fail.