error validations reactive form not display on my PC only ?

Question

problem

 

error validations reactive form not display on my PC only ?

 

meaning when user name is empty error not display but on another pc

 

same component work without change any thing 

 

I work on angular 7 project 

 

I work on reacive form all controls validation empty not work on my pc

 

i take ts and html component and put them in another project on nother pc 

 

it working without change any thing

 

so how to solve the problem and why this error display ?

 

my form as below 

<div *ngIf="error" class="alert alert-danger">{{error}}</div>
<h2>Reset Password</h2>
<form [formGroup]="ChangePasswordForm" (ngSubmit)="onSubmit()">
    <label>Reset Password</label>

    <div class="form-group">
      <label >UserName</label><br>
      <input type="text" formControlName="userName" [(ngModel)]="userservice.formData.userName" class="textboxclass"   [ngClass]="{ 'is-invalid': submitted && c.userName.errors }" />
      <div *ngIf="submitted && c.userName.errors" class="invalid-feedback">
          <div *ngIf="c.userName.errors.required">UserName is required</div>
          <div *ngIf="c.userName.errors.minlength">UserName must be at least 6 characters</div>
      </div>
    </div>