motioneye no login dialog

Installed motioneye (136) on DietPi v8.0.2 Device model : RPi 4 Model B (armv7l) with

sudo dietpi-software

and it seems to start

dietpi@DietPi:~$ sudo systemctl status motioneye.service
● motioneye.service - motionEye Server
   Loaded: loaded (/etc/systemd/system/motioneye.service; disabled; vendor preset: enabled)
   Active: active (running) since Tue 2022-01-11 17:19:22 CET; 9s ago
 Main PID: 1951 (meyectl)
    Tasks: 5 (limit: 4915)
   CGroup: /system.slice/motioneye.service
           ├─1951 /usr/bin/python /usr/local/bin/meyectl startserver -c /etc/motioneye/motioneye.conf
           └─1961 /usr/bin/python /usr/local/bin/meyectl startserver -c /etc/motioneye/motioneye.conf

Jän 11 17:19:22 DietPi systemd[1]: Started motionEye Server.
Jän 11 17:19:22 DietPi meyectl[1951]:     INFO: hello! this is motionEye server 0.42.1
Jän 11 17:19:23 DietPi meyectl[1951]:     INFO: main config file /etc/motioneye/motion.conf does not exist, using default values
Jän 11 17:19:23 DietPi meyectl[1951]:     INFO: cleanup started
Jän 11 17:19:23 DietPi meyectl[1951]:     INFO: wsswitch started
Jän 11 17:19:23 DietPi meyectl[1951]:     INFO: tasks started
Jän 11 17:19:23 DietPi meyectl[1951]:     INFO: mjpg client garbage collector started
Jän 11 17:19:23 DietPi meyectl[1951]:     INFO: server started

The problem is on the web-interface (Port 8765) i see the plain interface with DietPi and not much more. I cannot add camera and a click on settings just opens a half transparent Preferences slide with some settings that do not react on mouse or keyboard…

When i click on User Symbol then this message occurs:
“An error occured. Refreshing is recommended.”

There is no log or whatever that will tell me more about the Problem… Another

sudo systemctl status motioneye.service

gives only this output:

● motioneye.service - motionEye Server
   Loaded: loaded (/etc/systemd/system/motioneye.service; disabled; vendor preset: enabled)
   Active: active (running) since Tue 2022-01-11 17:19:22 CET; 10min ago
 Main PID: 1951 (meyectl)
    Tasks: 5 (limit: 4915)
   CGroup: /system.slice/motioneye.service
           ├─1951 /usr/bin/python /usr/local/bin/meyectl startserver -c /etc/motioneye/motioneye.conf
           └─1961 /usr/bin/python /usr/local/bin/meyectl startserver -c /etc/motioneye/motioneye.conf

Jän 11 17:27:42 DietPi meyectl[1951]:  WARNING: 403 GET /config/list/?_=1641918462896&_username=_&_signature=934fcf436a2fce150eb0158de489e2a28060d380 (192.168.100.2) 2.34m
s
Jän 11 17:28:11 DietPi meyectl[1951]:  WARNING: 403 GET /login/?_=1641918491794&_username=_&_signature=32704dee5549bb8ef0653f8aeddb0760752791e2 (192.168.100.2) 1.17ms
Jän 11 17:28:22 DietPi meyectl[1951]:  WARNING: 403 GET /config/list/?_=1641918502430&_username=_&_signature=46e2aa8106a6ad2babcdbe2d489acf7c479c9ac7 (192.168.100.2) 1.24m
s
Jän 11 17:28:22 DietPi meyectl[1951]:  WARNING: 403 GET /login/?_=1641918502784&_username=_&_signature=3b3e554b28313785016a944a449b65050be020bf (192.168.100.2) 1.11ms
Jän 11 17:28:36 DietPi meyectl[1951]:  WARNING: 403 GET /login/?_=1641918516082&_username=_&_signature=66cb2d189b4976929559efc0cfa97ac6f662f6f2 (192.168.100.2) 1.07ms
Jän 11 17:28:38 DietPi meyectl[1951]:  WARNING: 403 GET /config/list/?_=1641918518049&_username=_&_signature=a43858fb196848fa9e1097100bb8511f1edc89e9 (192.168.100.2) 1.64m
s
Jän 11 17:28:38 DietPi meyectl[1951]:  WARNING: 403 GET /login/?_=1641918518409&_username=_&_signature=a65861a896d166376116dbbce448046cd31fcded (192.168.100.2) 1.08ms
Jän 11 17:28:39 DietPi meyectl[1951]:  WARNING: 403 GET /config/list/?_=1641918519520&_username=_&_signature=87904a6cf3b73f6649a0ab1cd968aa93a3402f87 (192.168.100.2) 1.46m
s

I purged the motioneye package already twice and re-installed again - the error remains the same.

What can i do about this strange FE behaviour ?

You are running Debian Buster or Bullseye? Because motioneye is not working on Bullseye.

echo $G_DISTRO_NAME