[xubuntu-users] Help with Mint

[Thomas Blasejewicz]

Good evening
I know, this does not belong here, but for reasons I do not understand 
has the Mint mailing list died. I get:
----- The following addresses had permanent fatal errors -----
<linuxmint at librelist.com>
     (reason: 550 Host unknown)

Problem:
I installed Mint 17.1, 64-bit on a Dell Optiplex 745 (I intended to make 
this a "production machine" ...)
and was trying to figure out, how to make Wine work with Japanese software.
No success at all.
And maybe I did (touch?) something, although I don't know what.

The machine has been sitting here for a few days, during which I did not 
use it.
Today I tried to start it up and get:
"Cinnamon has crashed. Do you want to use it in fallback mode / restart?"
Neither choice does do anything.
Instead of the usual wallpaper I got a black screen with the usual icons 
(Home, Computer etc.) that do work somehow.
But the start menu is gone, richt clicking options are gone and I cannot 
log out or shut the computer down --- except by cutting the power.
Cutting the power and restarting the computer does not help at all.

I did try (which has helped before):
sudo apt-get update
sudo apt-get upgrade
at the end of which I am told, that the "locale en_US" is not supported.

Is there any way of getting this thing back on line, or is this just 
another case where I have to reinstall everything from scratch?
( I had to do THAT a million times already, because I do not know all 
the fancy computer techniques ...)

Thank you.
Thomas