In this scenario, you receive the following error message:
There is a duplicate key sequence "LYNCONLINE" for the 'urn:schema:Microsoft.Rtc.Management.Settings.Edge.2008:ProviderName' key or unique identity constraint.
To resolve this issue, remove the existing LyncOnline provider, and then run the original cmdlet again. Run both Get-CSHostingProvider and Get-CSPublicProvider cmdlets to see all existing providers and determine whether any providers have the same name as the name that you’re trying to create. (For example, determine whether any providers have the name "LyncOnline.")
If the existing LyncOnline connector is a hosting provider, use the following command to remove it:
Remove-CSHostingProvider –Identity LyncOnline
If the conflicting provider is a public provider, use the following command to remove it:
Remove-CSPublicProvider –Identity LyncOnline
This issue occurs because there is a public provider that has the duplicate name "LyncOnline configured in the topology. This can be verified by viewing the following settings in the Lync control panel:
In Lync 2010, click External User Access, and then click Provider.
In Lync 2013, click Federation and External Access, and then click SIP Federated Providers.