SharePoint Search Service upgrade to 2013 fails: "Inner Exception: An item with the same key has already been added."

Here's the situation:

• Upgrading a SharePoint Server 2010 Search Service Application dB to our SharePoint 2013 SP 1 development environment, using the Management Shell
• Running the following commands: 

$applicationPool= Get-SPServiceApplicationPool -Identity 'SearchService_AppPool'

$searchInst = Get-SPEnterpriseSearchServiceInstance -local

Restore-SPEnterpriseSearchServiceApplication -Name 'SearchServiceApplication' -applicationpool $applicationPool -databasename 'SearchServiceApplicationDB' -databaseserver SERVERNAME -AdminSearchServiceInstance $searchInst

• Creates the search dBs (crawl, links, analytics) successfully; however, in the end, I get....
• "Exception: Action 15.0.107.0 of Microsoft.Office.Server.Search.Upgrade.SearchAdminDatabaseSequence failed."

Looking at the ULS logs, I find the following:

Inner Exception: An item with the same key has already been added.
at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)     at Microsoft.Office.Server.Search.Administration.OOTBSchemaDefinition.FindAndFixExistingManagedProperties()     at Microsoft.Office.Server.Search.Administration.OOTBSchemaDefinition.InstallManagedProperties(Boolean upgrade)     at Microsoft.Office.Server.Search.Administration.OOTBSchemaDefinition.Upgrade()     at Microsoft.Office.Server.Search.Upgrade.UpdateAllOOTBProperties.Upgrade()     at Microsoft.SharePoint.Upgrade.SPActionSequence.Upgrade()

Exception: Action 15.0.107.0 of Microsoft.Office.Server.Search.Upgrade.SearchAdminDatabaseSequence failed.
at Microsoft.SharePoint.Upgrade.SPActionSequence.Upgrade()     at Microsoft.SharePoint.Upgrade.SPDatabaseSequence.Upgrade()     at Microsoft.Office.Server.Search.Upgrade.SearchDatabaseSequence.Upgrade()     at Microsoft.SharePoint.Upgrade.SPUpgradeSession.Upgrade(Object o, Boolean bRecurse)

Anyone encounter anything like this during their search upgrade process? I'm not honestly even sure what duplicate value to look for at this point, if I were to run a SELECT Id, ClassId, ParentId, Name, Status, Version, Properties FROM Objects on"SharePoint_Config" in SSMS. Any insight or opinions on the matter are welcome; and thanks to those who choose to reply to this, in advance.