While updating the website suddenly the menu does not any more allowing editing an entry. I can move menu entries around, but editing an existing or adding a new one is not possible. Just no reaction when I click on a button. Same in Backend no adding of a new entry possible.

The log entry that is triggered while clicking on new:

2016-12-21 10:09:26,217 5045 ERROR koina-cc openerp.http: Exception during JSON request handling.
Traceback (most recent call last):
  File "/opt/odoo/odoo-server/openerp/http.py", line 648, in _handle_exception    return super(JsonRequest, self)._handle_exception(exception)  
  File "/opt/odoo/odoo-server/openerp/http.py", line 685, in dispatch    result = self._call_function(**self.params)
  File "/opt/odoo/odoo-server/openerp/http.py", line 321, in _call_function    return checked_call(self.db, *args, **kwargs)
  File "/opt/odoo/odoo-server/openerp/service/model.py", line 118, in wrapper    return f(dbname, *args, **kwargs)
  File "/opt/odoo/odoo-server/openerp/http.py", line 314, in checked_call    result = self.endpoint(*a, **kw)
  File "/opt/odoo/odoo-server/openerp/http.py", line 964, in __call__    return self.method(*args, **kw)
  File "/opt/odoo/odoo-server/openerp/http.py", line 514, in response_wrap    response = f(*args, **kw)
  File "/opt/odoo/odoo-server/addons/bus/controllers/main.py", line 34, in poll    raise Exception("bus.Bus unavailable")
Exception: bus.Bus unavailable
2016-12-21 10:09:26,219 5045 INFO koina-cc werkzeug: 163.172.151.184 - - [21/Dec/2016 10:09:26] "POST /longpolling/pollHTTP/1.0" 200 -

I have no clue where to dig further.  Did try to uninstall (community OCA modules mainly), but without success so far. 

The error is connected to this particulare DB. Other DB on the server are ok. Same DB on another Server same error.