When you are in the process of creating a DAG, the process halts and returns the error "A server-side database availability group administrative operation failed with a transient error. Please try the operation again"
The clue is in the last part of the error "The fully qualified domain name for node "DAG" could not be found" this error is caused because the Cluster Name Object has not been pre created in Active Directory or alternatively the name of the Cluster Name Object computer account does not match the name of the DAG you are trying to add these computers to.
