VSTS Azure CLI - "Failed which: Not found az: null" Feb 5, 2018 • weznagwama If you’re getting the below error when trying to run an Azure CLI process step: ##[error]Unhandled: Failed which: Not found az: null Ensure you’re using a “Hosted VS 2017” agent oppose to a vanilla hosted agent. Reason being is that the vanilla agents don’t have the Azure CLI installed.