Hi I have tried to create a trigger to Lead Dedupe Management.
It worked perfectly when i inserted single record.
but when i upload through data loader am getting this error.

following is my code. Can any one help in createing the same for bulk inserts of lead through data loader.

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trigger LeadEventDedupeTestTrigger on Lead (before insert, before update)  {

Id rtID= [select Id,name from RecordType where name ='APAC - Open' limit 1].Id;

    for(Integer i=0;i<Trigger.new.size();i++){
            if(Trigger.new[i].Email !=null && Trigger.new[i].FirstName !=null && Trigger.new[i].LastName !=null){
                Contact ContactList = [Select Id ,Email,FirstName,LastName,Company__c,Account_Number__c,PIN__c,Ship_To__c,
                                            Created_Date__c,Primary_Account_Owner__c,Primary_Account_Owner_ID__c,Primary_Sales_Function__c,
                                            First_Order_Date__c,OwnerId,Owner.Name,Turnover__c
                                            FROM Contact WHERE Email =: Trigger.new[i].Email AND FirstName =: Trigger.new[i].FirstName AND LastName =: Trigger.new[i].LastName]; 
                {
                    Trigger.new[i].Existing_Contact__c = TRUE;
                    Trigger.new[i].Contact_Created_Date__c = ContactList.Created_Date__c;
                    Trigger.new[i].Contact_ID__c = ContactList.Id;
                    Trigger.new[i].Account_Number__c = ContactList.Account_number__c;
                    Trigger.new[i].Ship_To__c = ContactList.Ship_To__c;
                    Trigger.new[i].Contact_Company__c = ContactList.Company__c;
                    Trigger.new[i].Primary_Account_Owner__c = ContactList.Primary_Account_Owner__c;
                    Trigger.new[i].Primary_Account_Owner_ID__c = ContactList.Primary_Account_Owner_ID__c;
                    Trigger.new[i].Contact_Primary_Sales_Function__c = ContactList.Primary_Sales_Function__c;
                    Trigger.new[i].First_Order_Date__c = ContactList.First_Order_Date__c;
                    Trigger.new[i].Contact_Owner_ID__c = ContactList.Owner.Name;
                    Trigger.new[i].Turnover__c = ContactList.Turnover__c;
                    Trigger.new[i].PIN__c = ContactList.PIN__c;
                    
                    if(Trigger.new[i].Lead_Created_Date__c > ContactList.Created_Date__c){
                  if(Trigger.new[i].LeadSource == 'Supplier Lead Referral' || Trigger.new[i].LeadSource == 'Supplier Live Inquiry'){
                      Trigger.new[i].OwnerId = ContactList.OwnerId;
                  }
              else{
                Trigger.new[i].addError('Lead already exist as a Contact, Account Number : ' + ContactList.Account_number__c + ' / PIN : ' + ContactList.PIN__c + '/ Contact ID : ' + ContactList.Id);
              }
                }
            }
        }
    }
}