Alternative Desktops

[12cherithbrook]

Here is the problem. I am using Ubuntu 17.04 with Unity. I downloaded and installed an alternative Desktop Ubuntu Mate. I should have been able to log out into the sessions menu an select a chosen Desktop. However all I get is a login box which then reverts to the original Desktop. Any solutions please
Many Thanks

[westie457]

Check the small icons at the top of the login screen.
One of them should allow to change to a different session.

[michael-z-freeman]

You can also shut down the login manager, something like "sudo service gdm3 stop" and then start MATE or whatever from the command line. A simple search for that should suffice.