New Post: PropertyGrid error when opening collection

Hi,

Thanks for reporting this.
It is already fixed in v3.0.

You can wait for v3.0 Community edition to be released,
You can buy the Toolkit Plus edition (currently at v3.0 and v3.1 will be released in July 2016),
Or you can go in file Xceed.Wpf.Toolkit/CollectionControl/Implementation/CollectionControlDialog.xaml.cs,
In method : "Clone",
and at the beginning, add :
if( source == null )

    return null;