According to the Bootstrap migration guide:
Renamed .has-error to .has-danger.
However, that doesn't seem to work. Border and text has not been coloured.
For example:
<div class="form-group has-danger">
<label class="form-control-label" for="inputDanger1">Input with danger</label>
<input type="text" class="form-control form-control-danger" id="inputDanger1">
<div class="form-control-feedback">Sorry, that username's taken. Try another?</div>
<small class="form-text text-muted">Example help text that remains unchanged.</small>
</div>
Demo:
https://jsfiddle.net/uLa0spfm/
See Question&Answers more detail:os