Topic: SPDIF Sync problem

I’m still new to podium, but have experience with another daw.
In my setup, I’ve an external input connected via SPDIF.
To avoid sync problems I’ve to switch to externaly sync within podium.
That’s the way I’m used to.

But here I’m getting a problem:

What am I doing wrong?
Or is that caused by a limitation of the free version? So the message could be miss leading.

Thanks
Thomas