Having installed the CA Workload Automation DE R12 SPx Web client component successfully, when accessing the URL, the ALIAS fieled on the web page is getting auto-populated. There is also no OTHER option in the drop-down to select.
CA Workload Automation DE R12 SPx Web Client ON ANY platform
Check the README file located in the under the WADEWebClient_R12_* directory.
Here is an example from a Web Client r12 SP2:
# cat README
URL to access DE Web UI is
If you want to access DE Web UI using any other alias names such as localhost or ip address or with domain name, access the above URL first with a valid login. Only after you authenticate the logic of WEB UI using the above url, you can use URLs with alias name. If you miss this step and access the URL using alias name first, you will encounter an error "The login service is not available at the moment."