Hi,

Trying to deply a small change set from UAT to Production.
Controller "MyProfilePageControllerTest" works fine in UAT, but gives error in Production.
This controller is not affected in the Change Set. 

What is going on in this controller?
What can I change to pass the validation?

Error:

• Class Name - MyProfilePageControllerTest
• Method Name - testSave
• Error message - System.DmlException: Insert failed. First exception on row 0; first error: DUPLICATES_DETECTED, Use one of these records?: []
  Stack Trace: Class.MyProfilePageControllerTest.testSave: line 40, column 1

Code:

/**
 * An apex class that keeps updates of a portal user in sync with its corresponding contact.
   Guest users are never able to access this page.
 */
@IsTest public with sharing class MyProfilePageControllerTest {
    @IsTest(SeeAllData=true) static void testSetContactFields() {
        User u = [select title, firstname, lastname, email, phone, mobilephone, fax, street, city, state, postalcode, country
                           FROM User WHERE id =: UserInfo.getUserId()];

        Contact c = new Contact();

        MyProfilePageController.setContactFields(c, u);
        System.assertEquals(c.firstname, u.firstname, 'firstname should have been set as the firstname of the user for the contact');
        System.assertEquals(c.lastname, u.lastname, 'lastname should have been set as the lastname of the user for the contact');
    }

    @IsTest(SeeAllData=true) static void testSave() {
        // Modify the test to query for a portal user that exists in your org
        List<User> existingPortalUsers = [SELECT id, profileId, userRoleId FROM User WHERE UserRoleId <> null AND UserType='CustomerSuccess'];

        if (existingPortalUsers.isEmpty()) {
            User currentUser = [select id, title, firstname, lastname, email, phone, mobilephone, fax, street, city, state, postalcode, country
                                FROM User WHERE id =: UserInfo.getUserId()];
            MyProfilePageController controller = new MyProfilePageController();
            System.assertEquals(currentUser.Id, controller.getUser().Id, 'Did not successfully load the current user');
            System.assert(controller.getIsEdit() == false, 'isEdit should default to false');
            controller.edit();
            System.assert(controller.getIsEdit() == true);
            controller.cancel();
            System.assert(controller.getIsEdit() == false);

            Contact c = new Contact();
            MyProfilePageController.setContactFields(c, currentUser);
            c.LastName = 'TestContact';
            // START Company specific values...
            c.Company_Code__c = 'AAA';
            String rand = '00000000' + String.valueOf(Math.round(Math.random()*100000000));
            c.Personnel_Number__c = rand.subString(rand.length() - 8, rand.length());
            // END Company specific values...
            insert c;

            c.title = currentUser.title;
            c.firstname = currentUser.firstname;
            c.lastname = currentUser.lastname;
            c.email = currentUser.email;
            c.phone = currentUser.phone;
            c.mobilephone = currentUser.mobilephone;
            c.fax = currentUser.fax;
            c.mailingstreet = currentUser.street;
            c.mailingcity = currentUser.city;
            c.mailingstate = currentUser.state;
            c.mailingpostalcode = currentUser.postalcode;
            c.mailingcountry = currentUser.country;
            controller.save();
            System.assert(Page.ChangePassword.getUrl().equals(controller.changePassword().getUrl()));
            
        } else {
            User existingPortalUser = existingPortalUsers[0];
            String randFax = Math.rint(Math.random() * 1000) + '5551234';

            System.runAs(existingPortalUser) {
                MyProfilePageController controller = new MyProfilePageController();
                System.assertEquals(existingPortalUser.Id, controller.getUser().Id, 'Did not successfully load the current user');
                System.assert(controller.getIsEdit() == false, 'isEdit should default to false');
                controller.edit();
                System.assert(controller.getIsEdit() == true);

                controller.cancel();
                System.assert(controller.getIsEdit() == false);

                controller.getUser().Fax = randFax;
                controller.save();
                System.assert(controller.getIsEdit() == false);
            }

            // verify that the user and contact were updated
            existingPortalUser = [Select id, fax, Contact.Fax from User where id =: existingPortalUser.Id];
            System.assert(existingPortalUser.fax == randFax);
            System.assert(existingPortalUser.Contact.fax == randFax);
        }
    }
}