Trigger:

trigger Lead on Lead (after insert, after update) {
 
   if(trigger.isInsert || trigger.isUpdate){
  	 	ConvertLeadOnActiveService.convertLead(trigger.new);
   }
	
   if(trigger.isInsert){
		List<lead> leads = new List<Lead>();
		for(lead l : trigger.new){
 			if(l.PagerDuty_Account_ID__c != null) {
  			leads.add(l);
			}
		}
		CreatePddOnLeadService.createPDD(leads);
   }

   if(trigger.isUpdate){
		CreatePddOnLeadService.createPDD(CreatePddOnLeadService.filterPDIDIsNull(trigger.oldmap,trigger.new));
		ReassociatePDDToAccountService.movePDD(ReassociatePDDToAccountService.filterConverted(trigger.oldmap,trigger.new));
   }

}

Service Class

public with sharing class ConvertLeadOnActiveService {
   
    public static void convertLead(list<lead> convertList) {
   
     for (Lead lead : convertList) {
        if (lead.isConverted == false && lead.State__c == 'Active'){
      
         Database.LeadConvert lc = new Database.LeadConvert();
         lc.setLeadId(lead.Id);
      
          String oppName = lead.Company;
         lc.setOpportunityName(oppName);
      
         LeadStatus convertStatus = [SELECT Id, MasterLabel FROM LeadStatus WHERE IsConverted=true LIMIT 1];
         lc.setConvertedStatus(convertStatus.MasterLabel);
      
         Database.LeadConvertResult lcr = Database.convertLead(lc);
         System.assert(lcr.isSuccess());
      
      }
    }
  }
}

Test:

@isTest
public class TestConvertLeadonActive {
        static testMethod void verifyleadConvert(){
        
       Lead l = new Lead();
       l.FirstName = 'Test';
       l.LastName = 'Test';
       l.Company = 'Test, Inc.';
       l.Status = 'A. New-Open';
       l.State__c = 'trial';
       l.Email = 'test@test.com';
       l.State__c = 'Active';
       insert l;    
       
       List<Lead> retrieveLead = [SELECT id FROM Lead WHERE id =: l.Id AND isConverted = true];
        
      Integer size = retrieveLead.size();
      system.assertEquals(1,size);            

               
        }
    }

Error Message:

Class.TestConvertLeadonActive.verifyleadConvert: line 13, column 1
14:47:09.467 (8467634625)|FATAL_ERROR|System.DmlException: Insert failed. First exception on row 0; first error: CANNOT_INSERT_UPDATE_ACTIVATE_ENTITY, Lead: execution of AfterInsert

caused by: System.DmlException: ConvertLead failed. First exception on row 0; first error: UNKNOWN_EXCEPTION, An unexpected error occurred. Please include this ErrorId if you contact support: 1544795524-319229 (-1093901949): []