IBM BPM 8.5.5 - Performance Admin Console - Computer says "No"

So you're trying to access the IBM BPM 8.5.5 Business Performance Admin Console: -

https://bpm855.uk.ibm.com:9445/PerformanceAdmin/login.jsp

but the computer says "No"

Either the user name or password is wrong, or you are not authorized to log in to the Performance Admin Console.

Now we know that the Performance Admin Console runs on the Support cluster: -

IBM BPM 8.5.5 - What goes where ?

So let's see what's running: -

and then let's look at the User RunAs roles: -

So there's the answer ....

By default, the Deployment Environment admin user - deadmin ( in my case ) - is mapped to the tw-loader role

Once we log in using deadmin all is good: -

which is nice.