Preparing Active Directory is one of the most important part of Installing Skype for Business 2015. I prepared Schema without any issue but when i started “Prepare Current Forest”, its failed with following error.
Error: Object reference not set to an instance of an object.
Error: Value cannot be null. Parameter name: instanceToDelete
Error: An error occurred: “System.ArgumentNullException” “Value cannot be null.
Parameter name: instanceToDelete”
Simple solution is to prepare current forest for SFB 2015 using Skype for Business Server Management Shell.
Enable-CsAdForest -GroupDomain DomainName -GlobalSettingsDomainController DCName -GroupDomainController DCName -GlobalCatalog DCName
Enable-CsAdForest -GroupDomain Test.com -GlobalSettingsDomainController DC1.Test.com -GroupDomainController DC1.Test.com -GlobalCatalog DC1.Test.com
Note : You must have at least Enterprise Admin rights in Active Directory to prepare current forest either GUI or PowerShell.