Added debian repository to install more tool but no login option

Hello

to have a better way to work in the command line i wished to install vim-nox and multitail!
both gave a error
so i did add the debian repository too
apt update
apt install -y vim-nox
apt install -y multitail

both works so far
removed the debian repository and …

i can’t login anymore into the ucs GUI which is giving a error like

Interner Server-Fehler in "".
Request: 

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/univention/management/console/base.py", line 359, in __error_handling
    six.reraise(etype, exc, etraceback)
  File "/usr/lib/python2.7/dist-packages/univention/management/console/base.py", line 262, in execute
    function.__func__(self, request, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/univention/management/console/protocol/session.py", line 980, in handle
    self._handle_auth(request)
  File "/usr/lib/python2.7/dist-packages/univention/management/console/protocol/session.py", line 1001, in _handle_auth
    self.__auth.authenticate(request)
  File "/usr/lib/python2.7/dist-packages/univention/management/console/auth.py", line 104, in authenticate
    pam = PamAuth(locale)
  File "/usr/lib/python2.7/dist-packages/univention/management/console/pam.py", line 203, in __init__
    self.pam = self.init()
  File "/usr/lib/python2.7/dist-packages/univention/management/console/pam.py", line 254, in init
    pam.start('univention-management-console')
error: ('Kritischer Fehler - sofortiger Abbruch', 26)

doing a apt update give no error and nothing to install too.
is there a way to rescue this ucs or - will i have to set up it again?

have a nice day
vinc