Replication error message when you register a custom resolver to a merge replication in SQL Server 2014 (12.0.4439.1)

I am having a similar problem as described in this link https://support.microsoft.com/en-us/kb/2295460  I am running the latest version of SQL Server 2014 Standard as well on both sides (Publisher and Subscriber)

Microsoft SQL Server 2014 (SP1-CU5) (KB3130926) - 12.0.4439.1 (X64) 
Feb 15 2016 12:12:43 
Copyright (c) Microsoft Corporation
Standard Edition (64-bit) on Windows NT 6.3 <X64> (Build 9600: ) (Hypervisor)

I have merge replication setup for a table that contains 3 uniqueidentifier (null) columns one is the rowguid.  the publication is setup using that article with the default properties except for tracking level (column level), and Multi Column update (false). I also have a custom resolver that even when it looks like this fails with this message.

The schema of the custom DataSet object implemented in the business logic handler does not match the schema of the source DataSet object. Verify that the custom DataSet object has been correctly defined. 

public override ActionOnUpdateConflict UpdateConflictsHandler(DataSet publisherDataSet, DataSet subscriberDataSet, ref DataSet customDataSet, ref ConflictLogType conflictLogType, ref string customConflictMessage, ref int historyLogLevel, ref string historyLogMessage)
{
    customDataSet = publisherDataSet.Copy();
    conflictLogType = ConflictLogType.ConflictLogSubscriber;
    customConflictMessage = "Custom handler invoked";
    historyLogMessage = "A conflict was detected and handled by the custome handler.";
    historyLogLevel = 1;

    return ActionOnUpdateConflict.AcceptCustomConflictData;
}

The issue occurs when you update a column on one side (publisher) with an actual value (uniqueidentifer) and the other side same column with a null. this causes a conflict and the dataset schemas are not the same.  the datasets data column on the side with the unidentifier value (publisher in this case) has a System.String datatype, and the dataset data column on the side with the null (subscriber in this case) has a System.Guid data type.  

Please help, this needs to be fixed.  All other data types look to be fine, except for uniqueidentifier data types.