I am having trouble understanding this error and how its being caused. I am trying to pull user data in the form of JSON from an external website then Im trying to store that data in the contacts record. I know that every JSON string has a name, email and contact ID present. So how is it I can get an error like this? 

System.DmlException: Insert failed. First exception on row 0; first error: FIELD_CUSTOM_VALIDATION_EXCEPTION, Please provide either an Email Address or Phone Number: []

For testing purposes I had to create a mock response by implimenting the HTTPMockUp class, you can see my code below. Can I add some kind of logic check that would keep this from happening? im really close to passing all my orgs tests. 

Wrapper for JSON:
 

public class GDPRWrapper{

    public GDPRWrapper(List<GDPRData> templst){
            GDPRList = templst;
        }
    public List<GDPRData> GDPRList {get; set;}

    public class GDPRData {

        public Integer gdprId {get; set;}  //26636
        public String firstName {get; set;}
        public String lastName {get; set;}
        public String email {get; set;}
        public String phone {get; set;}
        public String accountName {get; set;}
        public String contactId {get; set;}    //AA111222333AAAe
        public String emailHash {get; set;}    //78fcb5ad502033c46d35abcecb3615bd92757fb0451485a19b27b7515f6d82d0
        public String createDate {get; set;}   //2018-05-17T15:19:37.000+0000
        public String responseDate {get; set;} //2018-05-21T10:38:53.000+0000
        public String notifyDate {get; set;}
        public boolean marketing {get; set;}
        public boolean security {get; set;}
        public boolean support {get; set;}
        public boolean contactPhone {get; set;}
        public boolean contactEmail {get; set;}
        public boolean contactOther {get; set;}
        public boolean invalid {get; set;}
        
        
    }
   public static List<GDPRData> parse(httpResponse json){
        return (List<GDPRData>) System.JSON.deserialize(json.getBody(), List<GDPRData>.class);
    }
 
    
}

Callout Class and updater:
 

public class JSONDeserialize {

    public GDPRWrapper wrapper {get;set;}
    public HttpResponse httpResponse {get;set;}
   
    
    
    @future(callout=true)
    public static void deserialize() {
        GDPRWrapper wrapper;
        HttpResponse httpResponse = new HttpResponse();
        
        Http h = new Http();
        HttpRequest request = new HttpRequest();
        
        request.setEndPoint('https://private');
        Blob headerValue = Blob.valueOf('d18849ea4155:d83ce6ef3dbe');
        String authorizationHeader = ('Basic ' + EncodingUtil.base64Encode(headerValue));
        
        
        request.setHeader('Authorization', authorizationHeader);
        request.setMethod('GET');
        HttpResponse response = new HttpResponse();
        try{
        response = h.send(request);
        
        
        System.debug('JSON RESPONSE: ' + response);
        List<GDPRWrapper.GDPRData> obj = GDPRWrapper.parse(response);
        wrapper = new GDPRWrapper(obj);
        
        System.assert(wrapper.GDPRList!=null);
        updateData(wrapper);
        }catch(JSONException j){
                    System.debug('An unexpected error has occured: ' + j.getMessage());
                }
              
        
      }
      
      
      public static void UpdateData(GDPRWrapper wrapper){
        List<Contact> contactPref = new List<Contact>();
        List<Contact> newContacts = new List<Contact>();
          
        for(Integer i = 0; i < wrapper.GDPRList.size(); i ++){
        if(wrapper.GDPRList[i].contactId.length() > 3){
                if(wrapper.GDPRList[i].contactId.subString(0,3) == '003'){
                    Contact toInsert = new Contact();
                    toInsert.firstName = wrapper.GDPRList[i].firstName;
                    toInsert.lastName = wrapper.GDPRList[i].lastName;
                    toInsert.email = wrapper.GDPRList[i].email;
                    toInsert.Email_Hash__c = wrapper.GDPRList[i].emailHash;
                    toInsert.Id = wrapper.GDPRList[i].contactId;
                    toInsert.Sales_and_Marketing__c = wrapper.GDPRList[i].marketing;
                    toInsert.Critical_Security_Notes__c = wrapper.GDPRList[i].security;
                    toInsert.Product_Information__c = wrapper.GDPRList[i].support;
                    toInsert.Contact_Via_Text__c = wrapper.GDPRList[i].contactPhone;
                    toInsert.Contact_Via_Email__c = wrapper.GDPRList[i].contactEmail;
                    contactPref.add(toInsert);
           
                }
            }
        else{
             Contact toInsert = new Contact();
             toInsert.firstName = wrapper.GDPRList[i].firstName;
             toInsert.lastName = wrapper.GDPRList[i].lastName;
             toInsert.email = wrapper.GDPRList[i].email;
             toInsert.Email_Hash__c = wrapper.GDPRList[i].emailHash;
             
             toInsert.Sales_and_Marketing__c = wrapper.GDPRList[i].marketing;
             toInsert.Critical_Security_Notes__c = wrapper.GDPRList[i].security;
             toInsert.Product_Information__c = wrapper.GDPRList[i].support;
             toInsert.Contact_Via_Text__c = wrapper.GDPRList[i].contactPhone;
             toInsert.Contact_Via_Email__c = wrapper.GDPRList[i].contactEmail;
             newContacts.add(toInsert);
        
        
        }
           
            
          
        
        }
          try{
              if(contactPref.size()>0){
                  upsert contactPref;
              }
              if(NewContacts.size()>0){
                 // insert NewContacts;
              }          
            } 
            catch(DmlException e){
                    System.debug('An unexpected error has occured: ' + e.getMessage());
                }
      
      }
     }

My test class:
 

@isTest
private class JSONDeserializeTest {

        @isTest static void testCalloutWithStaticResource(){

            Test.setMock(HttpCalloutMock.class, new Test_callApply1());
            JSONDeserialize.deserialize();
            System.assert(true);
        
        
        }


}

HttpCalloutMock implementation:

@isTest
global class Test_callApply1 implements HttpCalloutMock {
    // Implement this interface method
    global HTTPResponse respond(HttpRequest req) {
        // Optionally, only send a mock response for a specific endpoint
        // and method.
        //System.assertEquals('http://example.com/example/test', req.getEndpoint());
        //System.assertEquals('GET', req.getMethod());
        
        // Create a fake response
        HttpResponse res = new HttpResponse();
        res.setHeader('Content-Type','application/json');
        res.setBody('PRIVATE JSON DATA');
        res.setStatusCode(200);
        return res;
    }
}

My trigger:
 

trigger GDPR_Prefrences_Updater on Contact (after insert, after update) {
   if(System.IsBatch() == false && System.isFuture() == false && !Test.isRunningTest())
    {
        System.debug('i got triggered!!!');
        JSONDeserialize.deserialize();
    }

}

And here is a picture of my errors: