Replace the switch or cable
The switch or the cable between switch and PC seems to be defective.
Please contact your ETAS support or 3rd party hardware manufacturer.
You will find the phone numbers and e-mail addresses of your INCA support
on the ETAS web pages:
via the INCA Help menu:

Feedback
We would appreciate it very much if you could send as any feedback which might help us to improve the troubleshooting procedure.