1. You are not saving your hand histories in English and you are not running your PokerStars client in English:
PokerStars Configuration GuidePokerTracker 4 only supports English so hand histories need to be saved in English (PokerStars Client -> Settings -> Playing History -> Hand History) and the PokerStars client needs to be running in English (PokerStars Client -> Settings -> Global -> Language -> English).
2. You are pointing PokerTracker 4 to look for your PokerStars hands in your entire Windows user folder:
C:\Users\geert
This folder will contain thousands of other folders and files which have nothing to do with your PokerStars hands and directing PokerTracker 4 to search through your entire user folder will cause issues as it will not be able to locate the hands quickly and the volume of files will possibly cause the auto importer to lock up and even crash PokerTracker 4. What you need to do is save your PokerStars hands to a specific folder such as:
C:\Users\geert\StarsHH
and then set PokerTracker 4 to import from that same folder.