Vulcan/packages/vulcan-accounts/imports/ui/components/FormMessage.jsx

import React from 'react';
import { registerComponent } from 'meteor/vulcan:core';

export class AccountsFormMessage extends React.Component {
  render () {
    let { message, type, className = "message", style = {} } = this.props;
    message = _.isObject(message) ? message.message : message; // If message is object, then try to get message from it
    return message ? (
      <div style={ style } 
           className={[ className, type ].join(' ')}>{ message }</div>
    ) : null;
  }
}

registerComponent('AccountsFormMessage', AccountsFormMessage);