Hi,

I have an apex trigger that updates the event custom field with opportunity Stage Value.The trigger is working fine.Now i want to move it to production.But having issues with the test class.

When i run the test class i get the error First Exception on row 0 insufficient access to cross reference entity Id.
Please help! Iam very bad at test classes.


The trigger:
trigger trigeventOpp on Event (before insert, before update) {

   
    Set<Id> opIds = new Set<Id>();
    for(Event t : trigger.new){
        String wId = t.WhatId;
                if(wId!=null && wId.startsWith('006') && !opIds.contains(t.WhatId))
                { opIds.add(t.WhatId);
                } }
    // Pull in opp ids and related field to populate Event record
    List<Opportunity> taskOps = [Select Id, StageName from Opportunity where Id in :opIds];
    Map<Id, Opportunity> opMap = new Map<Id, Opportunity>();
    for(Opportunity o : taskOps)
    { opMap.put(o.Id,o);  } // Update custom task field with  opp field
    for(Event t : trigger.new)
    { String wId = t.WhatId;
     if(wId!=null && wId.startswith('006'))
     { Opportunity thisOp = opMap.get(t.WhatId);
      if(thisOp!=null){t.Opportunity_stage__c = thisOp.StageName;}
                                                 } }
}

The test class

@isTest
private class TheTestClassEvent {
  
public static testMethod void testocc(){
   
     // GET USER FROM USER TABLE...
     User u = [select name, Id  FROM user LIMIT 1];
      Account acc = new Account(
       name = 'temp validation account',
       Type = 'Prospect',
             Sub_Type__c='Merchant - Body',
             BillingCity='Dubai',
             BillingCountry='United Arab Emirates'
            
       );
         insert acc;
       
        Account accCreated = [Select Name From Account Where Id =: acc.Id LIMIT 1];
     // RUN AS USER...
     system.runAs(u)
     {
            Opportunity od = new Opportunity(
       Name = 'Distributor',
                AccountId=accCreated.id,
       Type='New Business',
                StageName='Pending',
                Stage_Notes__c='test opp',
                Edition__c='2014',
                LeadSource='Distributor',
                CloseDate=System.Today()
       );
         insert od;
           
           
           
            // TEST ADDING A NEW Event...                       
      Event eve = new Event(
       subject = 'Meeting test',
                whatId=od.Id
      
       );
         insert eve;
        

        
     }
     system.debug('----->>> RUNNING AS USER: ' + u.name);

   }       
}