Hello Community, 

Having an issue with a Bulk Apex Trigger challenge here, hope you guys can assist. 

Here is the critieria:
To complete this challenge, you need to add a trigger for Opportunity. The trigger will add a task to any opportunity inserted or updated with the stage of 'Closed Won'. The task's subject must be 'Follow Up Test Task'.The Apex trigger must be called 'ClosedOpportunityTrigger'
With 'ClosedOpportunityTrigger' active, if an opportunity is inserted or updated with a stage of 'Closed Won', it will have a task created with the subject 'Follow Up Test Task'.
To associate the task with the opportunity, fill the 'WhatId' field with the opportunity ID.
This challenge specifically tests 200 records in one operation.

Here is the Error Received:
Challenge not yet complete... here's what's wrong: 
There was an unexpected error in your org which is preventing this assessment check from completing: System.DmlException: Insert failed. First exception on row 0; first error: REQUIRED_FIELD_MISSING, Required fields are missing: [Discount_Percent__c]: [Discount_Percent__c]

Here Is My Code:

trigger ClosedOpportunityTrigger on Opportunity (after insert, after update) {
 
    List<Task> taskList = new List<Task>();
         
    for(Opportunity opp : Trigger.new) {
         
        //Only create Follow Up Task only once when Opp StageName is to 'Closed Won' on Create
        if(Trigger.isInsert) {
            if(Opp.StageName == 'Closed Won') {
                taskList.add(new Task(Subject = 'Follow Up Test Task', WhatId = opp.Id));
                }
            }
             
            //Only create Follow Up Task only once when Opp StageName changed to 'Closed Won' on Update
            if(Trigger.isUpdate) {
                if(Opp.StageName == 'Closed Won'
                && Opp.StageName != Trigger.oldMap.get(opp.Id).StageName) {
                    taskList.add(new Task(Subject = 'Follow Up Test Task', WhatId = opp.Id));
                }
        }      
    }
     
        if(taskList.size()>0) {       
            insert taskList;       
    }   
}

Please Note: I appended the code from SumitKumar from another post which worked for others as I changed my code to suit the suggested code.above. It seems I may have an insert dml exception issue maybe caused by an earlier code insertion. PLEASE ADVISE