Rofi-GUI-Window not visible

gistfile1.txt

I read 
https://www.linuxbabe.com/linux-server/fix-ssh-locale-environment-variable-error
and tried all tipps from there:

m@kubuntu-MS-7C37:~$ locale
locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_MESSAGES to default locale: No such file or directory
locale: Cannot set LC_ALL to default locale: No such file or directory
LANG=en_DE.UTF-8
LANGUAGE=en_GB
LC_CTYPE="en_DE.UTF-8"
LC_NUMERIC=de_DE.UTF-8
LC_TIME=de_DE.UTF-8
LC_COLLATE="en_DE.UTF-8"
LC_MONETARY=de_DE.UTF-8
LC_MESSAGES="en_DE.UTF-8"
LC_PAPER=de_DE.UTF-8
LC_NAME=de_DE.UTF-8
LC_ADDRESS=de_DE.UTF-8
LC_TELEPHONE=de_DE.UTF-8
LC_MEASUREMENT=de_DE.UTF-8
LC_IDENTIFICATION=de_DE.UTF-8
LC_ALL=
m@kubuntu-MS-7C37:~$ sudo localectl set-locale LANG=en_DE.UTF-8

m@kubuntu-MS-7C37:~$ rofi -show
(process:15674): Rofi-WARNING **: 13:19:12.540: Failed to set locale.
m@kubuntu-MS-7C37:~$ 

and no Rofi-GUI-Window visible

# sudo localectl set-locale LANG=en_DE.UTF-8

# sudo nano /etc/locale.gen
there was no 
de_DE.UTF-8

Update becouse there are different:

sudo localectl set-locale LANG=de_DE.UTF-8   
sudo nano /etc/locale.gen
de_DE.UTF-8

sudo nano /etc/ssh/ssh_config
Find this line:
SendEnv LANG LC_*
Add a # sign at the beginning to comment it out. Save and close the file.

i reboot the system an got again

m@kubuntu-MS-7C37:~$ rofi -show
and no Rofi-GUI-Window visible