React js href attribute requires a valid value. In general we use href in anchor tag now in react js we can add anchor tag but you need to make minor changes to make it work
// Instad <a href="#"> <FaTimes/> </a>
Use this
<a href="/#"> <FaTimes/> </a>
Or
<a href="#/"> <FaTimes/> </a>
Or
<a href="() => false"> <FaTimes/> </a>
Which ever suites your needs