diff --git a/app/models/ticket/escalation.rb b/app/models/ticket/escalation.rb
index 004bd3392..43f529b43 100644
--- a/app/models/ticket/escalation.rb
+++ b/app/models/ticket/escalation.rb
@@ -167,7 +167,7 @@ def escalation_calculation_get_sla
     sla_selected = nil
     sla_list = Cache.get( 'SLA::List::Active' )
     if sla_list == nil
-      sla_list = Sla.where( :active => true ).all
+      sla_list = Sla.where( :active => true )
       Cache.write( 'SLA::List::Active', sla_list, { :expires_in => 1.hour } )
     end
     sla_list.each {|sla|
@@ -221,53 +221,52 @@ def escalation_calculation_get_sla
       history_list.each { |history_item|
 
         # ignore if it isn't a state change
-        next if !history_item.history_attribute_id
-        history_attribute = History::Attribute.lookup( :id => history_item.history_attribute_id );
-        next if history_attribute.name != 'ticket_state'
+        next if !history_item['attribute']
+        next if history_item['attribute'] != 'ticket_state'
 
         # ignore all newer state before start_time
-        next if history_item.created_at < start_time
+        next if history_item['created_at'] < start_time
 
         # ignore all older state changes after end_time
         next if last_state_change && last_state_change > end_time
 
         # if created_at is later then end_time, use end_time as last time
-        if history_item.created_at > end_time
-          history_item.created_at = end_time
+        if history_item['created_at'] > end_time
+          history_item['created_at'] = end_time
         end
 
         # get initial state and time
         if !last_state
-          last_state        = history_item.value_from
+          last_state        = history_item['value_from']
           last_state_change = start_time
         end
 
         # check if time need to be counted
         counted = true
-        if history_item.value_from == 'pending'
+        if history_item['value_from'] == 'pending'
           counted = false
-        elsif history_item.value_from == 'close'
+        elsif history_item['value_from'] == 'close'
           counted = false
         end
 
-        diff = escalation_time_diff( last_state_change, history_item.created_at, sla_selected )
+        diff = escalation_time_diff( last_state_change, history_item['created_at'], sla_selected )
         if counted
-          puts "Diff count #{history_item.value_from} -> #{history_item.value_to} / #{last_state_change} -> #{history_item.created_at}"
+          puts "Diff count #{history_item['value_from']} -> #{history_item['value_to']} / #{last_state_change} -> #{history_item['created_at']}"
           total_time_without_pending = total_time_without_pending + diff
         else
-          puts "Diff not count #{history_item.value_from} -> #{history_item.value_to} / #{last_state_change} -> #{history_item.created_at}"
+          puts "Diff not count #{history_item['value_from']} -> #{history_item['value_to']} / #{last_state_change} -> #{history_item['created_at']}"
         end
         total_time = total_time + diff
 
-        if history_item.value_to == 'pending'
+        if history_item['value_to'] == 'pending'
           last_state_is_pending = true
         else
           last_state_is_pending = false
         end
 
         # remember for next loop last state
-        last_state        = history_item.value_to
-        last_state_change = history_item.created_at
+        last_state        = history_item['value_to']
+        last_state_change = history_item['created_at']
       }
 
       # if last state isnt pending, count rest