Just as a heads up to others. After the cloudformation script runs and you can access the TAC page. I thought that it wasn't connecting to the artifact repository and I kept rolling back the deployment. This last time, I got called in to a meeting and it ran for a while. When I came back it had gone from red to green. I think it might take a while for the Nexus server to come online, so give it a while.
Could you please clarify in which Talend Big Data Platform version/edition you are? With your subscription solution, could you please create a case on talend support portal so that we can give you a remote assistance through support cycle with priority?