I wrote a couple of triggers that duplicate opportunities when we set their stage to closed won, and then automatically create revenue schedules based on the products those opportunities have. They have been working well, but I started getting a weird error whenever I try to close an opp with more than one product. Here's a screenshot of the error:



For some reason, when it tries to duplicate this opp, if I only have one product on it, it will work, but once I add a second, it throws and error. I'll also attach the code for the "Create_Followup" trigger. I can upload the "EditSchedule" trigger too if that turns out to be part of the problem. Thanks for the help.

here's create_Followup. It's throwing an error when it tries to insert the opp product list.

trigger Create_followup on Opportunity (before update, after insert) {
    List<Pricebook2> standardBook = [SELECT Id FROM Pricebook2 WHERE Name = :'Ambition'];//Create an instance of the standard pricebook
    
    if(Trigger.isUpdate){
        List<Opportunity> listOppor = new List<Opportunity>();
        for (Opportunity o: Trigger.new){
            if (o.StageName == 'Closed Won' && o.Stage_Change__c == false){

                Opportunity oppNew = o.clone();
                oppNew.Name = oppNew.Name  + ' - Annual ' + o.CloseDate.year();
                
                if(o.Renewal_Date__c != null){
                oppNew.Renewal_Date__c = o.Renewal_Date__c.addYears(1);
                oppNew.CloseDate = o.Renewal_Date__c;
                oppNew.Contract_Start_Date__c = o.Renewal_Date__c;}
                
                oppNew.StageName = 'Discovery';
                oppNew.Probability = 25;
                oppNew.Parent_Opportunity__c = o.Id;
                
                
                oppNew.Pricebook2Id = standardBook[0].Id;//associate the standard pricebook with this opportunity
                
                oppNew.Is_Clone__c = true;
                listOppor.add(oppNew);
                o.Stage_Change__c = true;
                
            }

        }//end of for loop

        if(listOppor.size() > 0){
            insert listOppor;
            
            List<OpportunityContactRole> ocrList = [SELECT OpportunityId, ContactId, Role FROM OpportunityContactRole WHERE OpportunityId IN :Trigger.New];
            List<OpportunityContactRole> newOcrList = new List<OpportunityContactRole>();

            if(!ocrList.isEmpty()) {
                Map<Id, Id> oldOpNewOpIdMap = new Map<Id, Id>();
                for(Opportunity opNew : listOppor) {
                    oldOpNewOpIdMap.put(opNew.Parent_Opportunity__c, opNew.Id);
                }   
                for(OpportunityContactRole ocr : ocrList) {
                    OpportunityContactRole newOcr = new OpportunityContactRole();
                    newOcr.ContactId = ocr.ContactId;
                    newOcr.Role = ocr.Role;
                    newOcr.OpportunityId = oldOpNewOpIdMap.get(ocr.OpportunityId);
                    newOcrList.add(newOcr);
                }
                insert newOcrList;
            }
            
          List<OpportunityLineItem> oliList = [SELECT OpportunityId, PricebookEntryId, UnitPrice, Quantity, Duration__c, Payment_Terms__c, Discount FROM OpportunityLineItem WHERE OpportunityId IN :Trigger.New];
          List<OpportunityLineItem> newoliList = new List<OpportunityLineItem>();
          
          if(!oliList.isEmpty()) {
                Map<Id, Id> oldOpNewOpIdMap2 = new Map<Id, Id>();
                for(Opportunity opNew : listOppor) {
                    oldOpNewOpIdMap2.put(opNew.Parent_Opportunity__c, opNew.Id);
                }   
                for(OpportunityLineItem oli : oliList) {
                    OpportunityLineItem newOli = new OpportunityLineItem();
                    newOli.UnitPrice = oli.UnitPrice;
                    
                    newOli.PricebookEntryId = oli.PricebookEntryId;
                    newOli.Quantity = oli.Quantity;
                    newOli.Duration__c = 12;
                   
                    newOli.Payment_Terms__c = oli.Payment_Terms__c;
                    newOli.Discount = oli.Discount;
                    newOli.OpportunityId = oldOpNewOpIdMap2.get(oli.OpportunityId);
                    
                    
                    newoliList.add(newOli);
                }
                insert newoliList;
            }

            
        }
        
        

    }

    if(trigger.isInsert){
        try{
            //OpportunityLineItem[] lines = new OpportunityLineItem[0];
            //PricebookEntry entry = [SELECT Id, UnitPrice FROM PricebookEntry WHERE Pricebook2Id = :standardBook.Id AND Product2.ProductCode = 'ENTERPRISE_ANNUAL_UPFRONT'];
            List<Event> eventList = new List<Event>();
            //List<Note> noteList = new List<Note>();


            for(Opportunity o: Trigger.new){
                if(o.Is_Clone__c == true){

                    //noteList.add(new Note(ParentId=o.id,Title='Matt is the Apex_God',Body='Matt is the Apex_God',isPrivate=false));

                    //lines.add(new OpportunityLineItem(PricebookEntryId=entry.Id, OpportunityId=o.Id, UnitPrice=entry.UnitPrice, Quantity=1));

                    if(o.Renewal_Date__c != null){

                        DateTime myDateTime = o.Renewal_Date__c.addMonths(-10);
                        eventList.add(new Event(whatid=o.id,startdatetime=myDateTime,subject='Account Management Follow-Up', EndDateTime=myDateTime, IsAllDayEvent=true));
                        eventList.add(new Event(whatid=o.id,startdatetime=myDateTime.addMonths(2),subject='Account Management Follow-Up', EndDateTime=myDateTime.addMonths(2), IsAllDayEvent=true));
                        eventList.add(new Event(whatid=o.id,startdatetime=myDateTime.addMonths(4),subject='Account Management Follow-Up', EndDateTime=myDateTime.addMonths(4), IsAllDayEvent=true));
                        eventList.add(new Event(whatid=o.id,startdatetime=myDateTime.addMonths(6),subject='Account Management Follow-Up', EndDateTime=myDateTime.addMonths(6), IsAllDayEvent=true));
                        eventList.add(new Event(whatid=o.id,startdatetime=myDateTime.addMonths(8),subject='Account Management Follow-Up', EndDateTime=myDateTime.addMonths(8), IsAllDayEvent=true));
                        eventList.add(new Event(whatid=o.id,startdatetime=myDateTime.addMonths(10),subject='Account Management Follow-Up', EndDateTime=myDateTime.addMonths(10), IsAllDayEvent=true));
                        eventList.add(new Event(whatid=o.id,startdatetime=myDateTime.addMonths(10),subject='Renewal',EndDateTime=myDateTime.addMonths(10), IsAllDayEvent=true));
                        eventList.add(new Event(whatid=o.id,startdatetime=myDateTime.addMonths(9),subject='Sales Contract Follow-Up',EndDateTime=myDateTime.addMonths(9), IsAllDayEvent=true));

                    }//end of if

                }
            }
            //insert lines;
            insert eventList;
            //insert noteList;

        }
        catch(Exception e){

        }
    }
}