Set-ADForestMode Fails - referral was returned from the server

Attempting to upgrade the forest mode from 2003 to 2008R2, using the command:

Set-ADForestMode –identity %FOREST% –ForestMode Windows2008R2Forest

This was failing with the error:

Set-ADForestMode : A referral was returned from the server



I found the Active Directory Web Services Service hadn’t started.




After starting this service, the Set-ADForestMode command worked fine.