Introduced error screen if no overview is assigned to

app/assets/javascripts/app/controllers/ticket_overview.coffee

@@ -537,7 +537,7 @@ class App.TicketOverview extends App.Controller
       vertical: true
 
     @navBarController = new Navbar
-      el:   elLocal.first()
+      el:   elLocal.filter('.sidebar')
       view: @view
 
     @contentController = new Table
@@ -841,6 +841,20 @@ class Navbar extends App.Controller
 
   render: (data) =>
     return if !data
+    content = @el.closest('.content')
+    if _.isArray(data) && _.isEmpty(data)
+      content.find('.sidebar').addClass('hide')
+      content.find('.main').addClass('hide')
+      content.find('.js-error').removeClass('hide')
+      @renderScreenError(
+        el: @el.closest('.content').find('.js-error')
+        detail:     'Currently no overview is assigned to your roles. Please contact your administrator.'
+        objectName: 'Ticket'
+      )
+      return
+    content.find('.sidebar').removeClass('hide')
+    content.find('.main').removeClass('hide')
+    content.find('.js-error').addClass('hide')
 
     # do not show vertical navigation if only one tab exists
     if @vertical
@@ -918,6 +932,8 @@ class Table extends App.Controller
     overview = data.overview
     tickets  = data.tickets
 
+    return if !overview && !tickets
+
     # get ticket list
     ticketListShow = []
     for ticket in tickets

app/assets/javascripts/app/lib/app_post/overview_list_collection.coffee

@@ -58,7 +58,8 @@ class _Singleton
         if data.assets
           App.Collection.loadAssets(data.assets)
           delete data.assets
-        @overview[data.index.overview.view] = data.index
+        if data.index && data.index.overview
+          @overview[data.index.overview.view] = data.index
         @callback(view, data.index)
       error: =>
         @fetchActive[view] = false