# Expression Blend在編輯Surface2 WPF項目時崩潰

System.InvalidOperationException was unhandled
Message=The scene node must be a composite node to access properties.
Source=Microsoft.Expression.DesignSurface


The InvalidOperationException seems to be related accessing the UI thread from any other than it's parent (based on this and this). I do draw some polylines on top of the map layer later on, but that shouldn't break things, as my identical implementation works in a pure non-Surface wpf projet.