Improved error handling for assets if recored got deleted in meantime.

app/models/ticket/article/assets.rb

@@ -33,7 +33,9 @@ returns
     end
     if !data[ app_model_ticket ][ ticket_id ]
       ticket = Ticket.lookup(id: ticket_id)
-      data = ticket.assets(data)
+      if ticket
+        data = ticket.assets(data)
+      end
     end
 
     if !data[ app_model_article ]

app/models/user/assets.rb

@@ -61,6 +61,8 @@ returns
           next if data[:Role] && data[:Role][role_id]
 
           role = Role.lookup(id: role_id)
+          next if !role
+
           data = role.assets(data)
         end