Hi Everyone,

The Following error occurs in Apex trigger.

      Error: Apex trigger DistributorDiscountChangeTrigger caused an unexpected exception, contact your administrator: DistributorDiscountChangeTrigger: execution of AfterUpdate caused by: System.DmlException: Update failed. First exception on row 0 with id 0QLL00000001CRNOA2; first error: INVALID_CROSS_REFERENCE_KEY, invalid cross reference id: []: ()
 QuoteLineItem ID: 0QLL00000001CRNOA2 

DistributorDiscountChangeTrigger :(used to update the discount ,which enter in account and should updte the value in related QuoteLineItem)
trigger DistributorDiscountChangeTrigger on Account (after update) 
{
    if(checkRecursive.runOnce())
{
    Map<Id, Account> accByIds = new Map<Id, Account>();
       for ( Account acc: Trigger.NEW) 
    {
        System.debug('Inside FOR Loop');
        if ( acc.Distributor_Discount_Service__c != Trigger.oldMap.get(acc.Id).Distributor_Discount_Service__c || acc.Distributor_Discount_Product__c != Trigger.oldMap.get(acc.Id).Distributor_Discount_Product__c || acc.Distributor_Discount_Renewal__c != Trigger.oldMap.get(acc.Id).Distributor_Discount_Renewal__c) {
            accByIds.put( acc.Id, acc);
          System.debug('Account ID' +accByIds);    
        System.debug('Account ID' +accByIds.size());    
        }
    }
    
    Map<Id, Opportunity> oppByIds = new Map<Id,Opportunity>( [ SELECT Id,Distributor__c FROM Opportunity WHERE Distributor__c IN: accByIds.keySet() AND IsClosed = FALSE]);        
       System.debug('Opportunity ID' +oppByIds.size());
 List<QuoteLineItem> qlitmp = [select id,quote.opportunity.Distributor__c,quote.opportunity.Override_Renewal_Discount__c,quote.opportunity.RecordType.name,Distributor_Discount_1__c,quote.opportunity.Distributor__r.Distributor_Discount_Renewal__c,product2.family,quote.opportunity.Distributor__r.Distributor_Discount_Service__c ,quote.opportunity.Distributor__r.Distributor_Discount_Product__c from quotelineitem where quote.opportunity.ID IN: oppByIds.keySet()]; 
     List<Opportunity> oppqt = [ SELECT Id,RecordType.name ,Override_Renewal_Discount__c,Distributor__r.Distributor_Discount_Renewal__c,Distributor__r.Distributor_Discount_Service__c,Distributor_Discount_Product_Temp__c,Distributor_Discount_Service_Temp__c,Distributor__c FROM Opportunity WHERE Id IN: oppByIds.keySet()];
      System.debug('Opportunity -list'+oppqt.size());   
     
    
    if ( !accByIds.isEmpty() ) 
    {
        System.debug('Inside if Loop');
        
       
         for ( Opportunity qt: oppqt ) 
         {
        /******* NST's Record Type == Service Renewal ***************/   //opp
               
                  if(qt.RecordType.name=='Service Renewal' && qt.Override_Renewal_Discount__c==false)
        { 
            System.debug('inside if');
            qt.Distributor_Discount_Service_Temp__c=  qt.Distributor__r.Distributor_Discount_Renewal__c;
        
             System.debug('Distributor_Discount_Renewal__c '+  qt.Distributor_Discount_Service_Temp__c); 
          
        }
      else  if(qt.RecordType.name=='Service Renewal' && qt.Override_Renewal_Discount__c==true)
        { 
            System.debug('inside if');
            qt.Distributor_Discount_Service_Temp__c=  qt.Distributor__r.Distributor_Discount_Service__c;
        
             System.debug('Distributor_Discount_Service__c '+  qt.Distributor_Discount_Service_Temp__c); 
          
        }
             
              /*******EOF NST's Record Type == Service Renewal ***************/
//
    else if ( qt.Distributor__c != null) 
    {
                qt.Distributor_Discount_Product_Temp__c = accByIds.get( qt.Distributor__c ).Distributor_Discount_Product__c;
               System.debug('opportunity.Distributor_Discount_Product_Temp__c '+  qt.Distributor_Discount_Product_Temp__c); 
               qt.Distributor_Discount_Service_Temp__c= accByIds.get( qt.Distributor__c ).Distributor_Discount_Service__c;
             System.debug('opportunity.Distributor_Discount_Service_Temp__c '+  qt.Distributor_Discount_Service_Temp__c); 

           }   
               
         }
         update oppqt;//opp
        
        
    }    
          for(quotelineitem qlitemp: qlitmp)
             {
                 system.debug('1');
                 if(qlitemp.quote.opportunity.RecordType.name=='Service Renewal' && qlitemp.quote.opportunity.Override_Renewal_Discount__c==false)
        { 
            system.debug('1-false');
           
           qlitemp.Distributor_Discount_1__c=qlitemp.quote.opportunity.Distributor__r.Distributor_Discount_Renewal__c;
         }
              else if(qlitemp.product2.family=='Service' && qlitemp.quote.opportunity.Distributor__c != null)
        {
            system.debug('12');
                 qlitemp.Distributor_Discount_1__c=qlitemp.quote.opportunity.Distributor__r.Distributor_Discount_Service__c ; 
        }
                 else if(qlitemp.product2.family=='product' && qlitemp.quote.opportunity.Distributor__c != null)
                 {
                     system.debug('13');
                     qlitemp.Distributor_Discount_1__c=qlitemp.quote.opportunity.Distributor__r.Distributor_Discount_Product__c ; 
                 }
                
         }  
        system.debug('qlitmp'+qlitmp);
        update qlitmp; //qli 
             
 
     
        
        /************************** NST Product Service Update to TEMP ***********************/
        Map<Id, NST__c> nstdisByIds = new Map<Id,NST__c>( [ SELECT Id, Distributor_Account__c FROM NST__c WHERE  Distributor_Account__c IN: accByIds.keySet() AND NST_Status__c = 'Draft']);        
       System.debug('nstdisByIds ID' +nstdisByIds.size());

     List<NST__c> nstdis = [ SELECT Id,recordtype.id,recordtype.name,Distributor_Account__r.Distributor_Discount_Renewal__c,Distributor_Account__r.Distributor_Discount_Product__c,Distributor_Account__r.Distributor_Discount_Service__c, Product_Contractual_Discount_Temp__c,Service_Contractual_Discount_Temp__c,Distributor_Account__c FROM NST__c WHERE Id IN: nstdisByIds.keySet()];
    System.debug('nstdis -list'+nstdis.size());   
           for ( NST__c qt: nstdis ) 
         {
            System.debug('Inside FOr');
             /******* NST's Record Type == Service Renewal ***************/
        if(qt.RecordType.name=='Service Renewal')
        { 
            System.debug('inside if');
            qt.Service_Contractual_Discount_Temp__c=  qt.Distributor_Account__r.Distributor_Discount_Renewal__c;
             System.debug('Distributor_Discount_Renewal__c '+  qt.Service_Contractual_Discount_Temp__c); 
        }
        
         /******* End of NST's Record Type == Service Renewal ***************/
    else if ( qt.Distributor_Account__c != null) 
    {
                qt.Product_Contractual_Discount_Temp__c = accByIds.get( qt.Distributor_Account__c ).Distributor_Discount_Product__c;
               System.debug('opportunity.Product_Contractual_Discount_Temp__c '+  qt.Product_Contractual_Discount_Temp__c); 
               qt.Service_Contractual_Discount_Temp__c=  accByIds.get( qt.Distributor_Account__c ).Distributor_Discount_Service__c;
             System.debug('opportunity.Service_Contractual_Discount_Temp__c '+  qt.Service_Contractual_Discount_Temp__c);  
           }       
         }

      update nstdis;  
        system.debug('Updated'+nstdis.size());
           system.debug('Updated'+nstdis);
        /*************************************************************************************/
        
        
    }
}

Please advice,

Thanks
Sumitha P