PROFINET Device app - Error code CF81FD12 - Aborted: AR protocol violation

Hello,

I'm using the PROFINET Device app and the CoDeSys fieldbus libaries, to establish a PN communication between a ctrlX PN controller and a SINAMICS S120 (PROFINET GSDML - SINAMICS S120). 

The device tree looks like this:

What does this error mean and how can I solve this?

Thanks in advance 🙂