Bootstrap 4 input error

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/css/bootstrap.min.css" integrity="sha384-rwoIResjU2yc3z8GV/NPeZWAv56rSmLldC3R/AZzGRnGxQQKnKkoFVhFQhNUwEyJ" crossorigin="anonymous">

<!--
  Title: bootstrap 4 input error
-->
<!--Go to https://www.w3schools.com/bootstrap4/bootstrap_forms.asp for more info-->
<form action="/action_page.php" class="was-validated">
  <div class="form-group">
    <label for="uname">Username:</label>
    <input type="text" class="form-control" id="uname" placeholder="Enter username" name="uname" required>
    <div class="valid-feedback">Valid.</div>
    <div class="invalid-feedback">Please fill out this field.</div>
  </div>
  <div class="form-group">
    <label for="pwd">Password:</label>
    <input type="password" class="form-control" id="pwd" placeholder="Enter password" name="pswd" required>
    <div class="valid-feedback">Valid.</div>
    <div class="invalid-feedback">Please fill out this field.</div>
  </div>
  <div class="form-group form-check">
    <label class="form-check-label">
      <input class="form-check-input" type="checkbox" name="remember" required> I agree on blabla.
      <div class="valid-feedback">Valid.</div>
      <div class="invalid-feedback">Check this checkbox to continue.</div>
    </label>
  </div>
  <button type="submit" class="btn btn-primary">Submit</button>
</form>

Source: stackoverflow.com

Similar codes

18 votes193 views6 answers
Bootstrap5 cdn
Javascript Bootstrap
0 vote202 views1 answer
Bootstrap-navbar-container-fluid
CSS Bootstrap
0 vote180 views1 answer
How to add bootstrap to vue js
Javascript Bootstrap
15 votes191 views3 answers
Bootstrap 4 tooltip
Javascript Bootstrap
1 vote210 views2 answers
How to navigate with navintems for react-bootstrap without refreshing the whole page
Javascript Bootstrap
0 vote214 views2 answers
Laravel bootstrap 5 install popper.js error
Javascript Bootstrap
33 votes201 views3 answers
React native bootstrap
Javascript Bootstrap
-1 vote185 views1 answer
Bootstrap prevent dropdown from closing on click
Javascript Bootstrap
0 vote198 views1 answer
Which react-bootstrap component you will use for width: 100% across all viewport and device sizes
Javascript Bootstrap
24 votes199 views5 answers
Open bootstrap modal with javascript
Javascript Bootstrap