In same cases upon login the following warning is displayed:

This usually happens when a browser bookmark/favourite link is being used whichs links to the login page. Using the login link as a bookmark causes the system to show this message because in that case it does not know the correct context of which Tngelo client server you want to be redirected after successful login.

solution The correct link to use in a bookmark/favourite will be shown in the browser address bar AFTER successful login.