The user has e.g. several browser tabs open with different TVB pages.
In one tab, the user logs out.
Then she reloads a different tab: Expectedly, she gets thrown back into the user section with a message saying "Login required".
That's fine up to this point.
The user is now stuck in the URL http://127.0.0.1:8080/tvb which HAS NO TOOLBAR!
Therefore, she can't log in anymore.
Doing the login again in a different browser tab and reloading */tvb after that doesn't change anything.
She has to get the idea to click on the footer's "User" link to get a toolbar again.
P.S.: This "dead-end" page still shows the original TVB page's name in the browser's title bar after many reloads.