The asset property is not editable. -or- Cannot check validity for a property not being edited in AppearanceAssetEditScope. -or- Asset property is already connected to one asset.
Remarks
Cannot add a connected asset if one is already connected. Use RemoveConnectedAsset() to avoid an exception being thrown. A new preset asset is created and connected to the property. For “UnifiedBitmap”, it contains an empty property unifiedbitmap_Bitmap.