xClassification: Manual Re-Structuring/Editing

Hello Everyone,

I am currently struggling with xClassification and I need some help/insight.

My current client created an xClassification structure, xClass and xProperties, sometime ago from and Engineering context.
As a corporate goal they are now challenged to create an Enterprise xClass and xProperties structure that will be used to publish, from PLM, to a Convergence system, Oracle EBS, and Oracle Fusion using an Enterprise classification structure.

So My current challenge is to updated the current xClass-xProperty structure to the the hierarchy while  preserving all the current/existing xProperty data.

Thus far I have been able to:
1) Rename all xClass items required
2) Generate the [From_RefId - To_Refid] string that establishes the
          xClass Hierarchy xClassificationTree.classification_hierarchy
3) Align xClass_xPropertyDefinition with xClass_xProperty_Flatten with
               xClass.xproperties_sort_order

The ClassificationTree loads as shown below

But when I try to save the xClassification tree I get this error:

I found the Error String in {Aras.Server.Core.dll}. internal class XTreeMigrationModel but, I'm not sure what it is actually doing to throw the exception. Below is the code snippet that throws the exception.