Hi Thomas Van Damme
Go to ALIGNMENT -> SETTINGS - DISTORTION MODEL and change it from the default BROWN3 to K + BROWN4 + TT
make a back-up save of the whole project, DELETE the COMPONENTS already there and then realign the project and check the results.
What camera and lens are you using there ?
Can you make a screenshot of your actual ALIGNMENT settings ?
Screenshot 2016-09-09 10.19.54.png