Hi ERobishaw,
I regret for the delayed response.
Our latest version (from v5.1) of Diagram is completely a new version and it has been fully refactored. These are mainly to make the control more stable, reliable and easy to use.
1. The PropertyEventArgs has been modified and separated into PropertyChangingEventArgs and PropertyChangedEventArgs classes.
You can find all the EventArgs classes in the Diagram.Base\Src\Services\_delegates.cs file.
2. The NodeCollectionEventArgs and ConnectionCollectionEventArgs has been moved and merged into a single class called "CollectionExEventArgs" class.
3. LinkPort class has been modified and please use EnpPoint,HeadEndPoint or TailEndPoint classes instead. You can find these classes under Base\Diagram.Base\Src\Entities\AnchoringPrimitives folder.
4. LinkFactory and NodeTracker classes are no more available with our latest verison of Diagram.
Also I have created a migration document that has the details about how to migrate the 4.4 version of samples to latest version:
http://www.syncfusion.com/Support/user/uploads/Migration_64aab1e9.zip Please try this and let me know if this helps.
Thanks,
Melba