After changing the language at a user on my PC and login later,
there was just the mouse pointer on the black screen.
The mouse was movable but no input was possible.
First I had to disable the auto login by booting from another
system and changing the settings.

By using another user account I found out, that the input method
in the menu list changed by changing the language from:
"None" to "Maliit". There were just this 2 methods to choose.

I found the settings here:

/home/anybody/.xinputrc

and it looked like this:


# im-config(8) generated on Wed, 10 May 2017 05:16:13 +0200
run_im maliit
# im-config signature: 94064edc29a4bad6fe34bdba7470b3ba -


So I copied with root rights the settings from my good user account,
to the settings of the bad and commented the bad out.
I wanted to let the old bad one in the list to see later how it was.

Now it looks like this

# im-config(8) generated on Wed, 10 May 2017 05:16:13 +0200
# run_im maliit
# im-config signature: 94064edc29a4bad6fe34bdba7470b3ba -
#
# im-config(8) generated on Wed, 10 May 2017 19:04:32 +0200
run_im xim
# im-config signature: 5c2f3c7151756c6673a558b9201af3c5 -


So just " run_im xim " is active - and IT WORKS!

I posted this because I didn't find help in the net and
others can try this if somebody else has this problem.

just taking this out of zero reply status.

linuxfriedel, you might want to mark this thread [Solved].