FIELD_CUSTOM_VALIDATION_EXCEPTION

Question

I get the following error:

FIELD_CUSTOM_VALIDATION_EXCEPTION : Automatic email loop has been terminated

I have made a trigger on cases to kill email loops. When I google the error I get that it could be a missing field, where I am left in the dark where i have no clue which field should be missing and there are no validation rules on cases. Here is my code, please some explanation:

trigger beforeInsertOnCaseLoopKiller on Case (before insert) {
    // Will not process new email if there are at least 4 emails from
    // the same email address with the same subject and the previous email
    // was less than 5 minutes old.

    case[] c = trigger.new;

    case[] check = [select ID, CreatedDate, subject from Case where SuppliedEmail = :c[0].SuppliedEmail and subject = :c[0].subject and isclosed = false order by CreatedDate desc];
    system.debug(c[0].SuppliedEmail);
    system.debug(c[0].subject);

    if(c[0].Subject != null) {  
        //We have a subject, proceed.
        if(c[0].subject.contains('[ ref:')){
            //No Errors.  Email should be attached to the case.
        }else{
            if(check.size() > 3){
                if((check[0].createddate.addMinutes(5) > System.now()) && check[0].subject.contains(c[0].subject)){
                    //Loop Was Killed.
                    Messaging.SingleEmailMessage message = new Messaging.SingleEmailMessage();                    
                    message.toAddresses = new String[] {[SELECT Loopkiller_Email_support__c FROM Loopkiller__c LIMIT 1][0].Loopkiller_Email_support__c};
                    message.optOutPolicy = 'FILTER';
                    message.subject = 'Email loop caused';
                    message.plainTextBody = 'An email loop has been caused by case '+c[0].subject + '\n' + 'This loop was generated by email adres '+ c[0].SuppliedEmail + '.';
                    Messaging.SingleEmailMessage[] messages = 
                    new List<Messaging.SingleEmailMessage> {message};
                     Messaging.SendEmailResult[] results = Messaging.sendEmail(messages);
                    if (results[0].success) {
                    System.debug('The email was sent successfully.');
                    } else {
                            System.debug('The email failed to send: '
                              + results[0].errors[0].message);
                        }

                    c[0].addError('Automatic email loop has been terminated');

                }else{
                    //New Case should be created now!       
                }
            }
        }
    }
}

Answer 1

You are directly causing this error (if I recall, you were looking to create some unit tests for this trigger). As noted in the comments, the text of the error message matches the text that you're sending to addError() in your code.

When you add an error message to a record in an appropriate trigger context variable using addError() in a before trigger, that will cause the execution of your trigger to stop. This is noted in the documentation on SObject methods for addError().

From that page:

addError(errorMsg)

Marks a record with a custom error message and prevents any DML operation from occurring.

Usage

When used on Trigger.new in before insert and before update triggers, and on Trigger.old in before delete triggers, the error message is displayed in the application interface.

When used in Visualforce controllers, the generated message is added to the collection of errors for the page. For more information, see Validation Rules and Standard Controllers in the Visualforce Developer's Guide.

The class of error that you get when this happens is FIELD_CUSTOM_VALIDATION_EXCEPTION, which is a bit misleading (as it has nothing to do with validation rules. If anything, it's indicative of when, in the order of execution, this happens), but that's the way Salesforce does things.