At least on my end disconnect no longer works in Vray for Revit7.1 when connected to Vantage 2.8.1. Connecting is all good so not a big issue.
Dear tehamnes​,
Thanks for reporting this! We’ve confirmed there’s a bug in the latest version of V-Ray 7 for Revit where the “Disconnect Chaos Vantage” button doesn’t respond. The issue is logged [REVIT-4738] and under investigation. We’ll keep you posted on updates