“ERROR: TF55030: Rename Data Tier failed.  Please verify that the supplied Data Tier name is a valid Team Foundation Data Tier name, that the Data Tier can be accessed on the network and that you have administrative rights.”

Most chances that the problem is because you have shutdown your old TFS.

In order to fix the problem just load your old TFS and rerun the command.

In case that doesn’t help run the following command line:

Set TfsDetailedErrors=1

Rerun the RenameDT command, now you will get more details on the error so you can troubleshot the problem.

Have Fun!!!