hi,guys, a developer beginner here
i try to override a new event creation button with the standard new and save fuction but failed,
could some body tell me what is wrong with the save part, i cannot save properly.

<aura:component implements="lightning:actionOverride">
  <aura:handler name="init"  value="{!this}"  action="{!c.createAccount}"/>  
</aura:component>

({
 createAccount: function (component) {
     
        var createRecordEvent = $A.get('e.force:createRecord');
        if ( createRecordEvent ) {
             
            createRecordEvent.setParams({
                'entityApiName': 'Event'
            });
            createRecordEvent.fire();
        } else {
            /* Create Record Event is not supported */
            alert("Event creation not supported");
        }
    }
})

Hi,
When I am try solving this challenge for Opportunity Checkbox , I get this error.
The validation rule is right no error. I also followed  the answers provided in the solution. Everything seems to be good.Pls lmk 
what debugging can be done.

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: CANNOT_INSERT_UPDATE_ACTIVATE_ENTITY, t2: execution of BeforeInsert caused by: System.NullPointerException: Argument cannot be null. Class.trigger_class.check_opp: line 13, column 1 Trigger.t2: line 2, column 1: []