When attempting to merge the existing OCS estate into Lync I get the following error:

2011-03-14 17:25:46 INFORMATION :  User input file path: "C:\Users\risual\AppData\Local\Temp\TopologyBuilder\2011_03_14_17_25_44\MergeTopologyInput.xml"
2011-03-14 17:25:46 ERROR :  Total number of validation errors: "1"
2011-03-14 17:25:46 ERROR :  Topology error description: "There was a problem validating the topology XML against the XSD that defines the schema."
2011-03-14 17:25:46 ERROR :  Topology error instances: "[ System.Xml.Schema.XmlSchemaValidationException: There is a duplicate key sequence 'urn:application:Rgs SipServer Primary Mtls' for the 'urn:schema:Microsoft.Rtc.Management.Deploy.ServiceRoles.2008:ComponentPortId' key or unique identity constraint. ][ System.Collections.Generic.List`1[System.Object] ]"
2011-03-14 17:25:46 ERROR :  Topology error reason: "FailedSchemaValidation"
2011-03-14 17:25:46 ERROR :  There were errors while creating and validating a topology.
2011-03-14 17:25:46 WARNING :  Total number of errors is 1
2011-03-14 17:25:46 WARNING :  Total number of warnings is 0
2011-03-14 17:25:46 ERROR : BuildTopologyError

Found this useful link which has some pointers on trying to locate and troubleshoot the issue:

http://viammercer.blogspot.com/2010/12/merge-topology-failure-microsoft-lync.html

Personally, the above didn’t work for me.

Because I knew it was an RGS error (‘urn:application:Rgs SipServer Primary Mtls’) I ran a validation against the RGS in OCS and it came back with an error reporting that it was expecting one CN record but it was in fact set to another. I tried to set the correct CN in ADSI Edit but just received an error.

How did I fix this? Well, luckily for me the customer wasn’t using the RGS so i deactivated it. After it had been deactivated the OCS to Lync merge process completed without any errors.

Hope this helps

Neil