The problem is solved!
Thanks a lot!
Plamen
HI,
Try replacing this line:
filterMember.IsExpanded = true;
with this:
this.Dispatcher.BeginInvoke(() => { filterMember.IsExpanded = true; });
There are two occurrences of it in the ExpandToLevelCB.xaml.cs file.
This should fix your problem. I'm afraid, however that in more complex scenarios with lots of levels and lots of different selections there might be similar problems. Those are fixed in the 11.1 release version of the product, which is coming soon.
I hope this is helpful.
All the best,
Atanas